RU2531202C1 - Glue composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: glue composition contains polychloroprene caoutchouc nairit NT, butylphenolformaldehyde resin 101K, thiuram, zinc oxide, magnesium oxide, organic solvent, representing a mixture of ethylacetate and nefras (petroleum solvent), modified milled polycaproamide fibre of type 23 KHTC, obtained by its preliminarily processing by non-equilibrium low-temperature plasma of a low frequency glow AC discharge in a vacuum chamber for 2 minutes.

EFFECT: increased strength in conglutination of vulcanised rubber to each other.

2 tbl

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 C 09 J 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 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 an adhesive composition comprising polychloroprene rubber nairit NT, butylphenol formaldehyde resin 101K, thiuram, zinc oxide, magnesium oxide, a modifier and an organic solvent, which is a mixture of ethyl acetate and nefras. As a modifier, pre-chopped polycaproamide fiber of grade 23 KNTS is used (Pat. 2448997, Russia, С09J 11/00; Publ., June 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 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, crushed polycaproamide fiber grade 23 KNTS and use modified polycaproamide fiber of grade 23 KNTS obtained by pretreatment with a nonequilibrium low-temperature plasma of a glowing low-frequency discharge alternating current in a vacuum chamber for 2 minutes, with the following ratio of components, parts by weight: 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 solvent - 800.0, modified chopped polycaproamide fiber brand 23 KNTS - 1.0-5.0.

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 D.A., Petrova A.V. Polymer adhesives. M: Chemistry, 1983).

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

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

To modify the chopped polycaproamide fiber of grade 23 KNTS, the processing method in a glow low-frequency discharge of alternating current (50 Hz) was used. Processing time 2 min.

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 on their surface, the number of hydrophilic functional groups that improve the wettability of the fibers increases, which leads to their more uniform distribution in the adhesive film and, as a result, to an increase in adhesive and cohesive strength.

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 pretreating it in a nonequilibrium low-temperature plasma — in a glowing low-frequency discharge of alternating current (50 Hz). A special teflon electrode holder was placed in the vacuum reaction chamber, on which metal electrodes were mounted. In direct contact with the lower electrode, a special metal frame was placed on which the processed fibers were placed. The installation was pumped out to a pressure of 10 ^-2 Pa using a foreline pump, the pressure in the reaction chamber was monitored using a vacuum gauge. Then, purified air was injected through the inlet system to a pressure of 15-20 Pa and voltage was applied to the electrodes from an alternating current source. Power was supplied from the network through a step-up transformer, with a current frequency of 50 Hz, a current of 100 mA was measured with an ammeter. The fiber processing time is 2 min (Gilman AB, Drachev A.I., Kuznetsov A.A., Lopukhova G.V., Potapov V.K. Chemistry of high energies. 1997. V. 31. No. 2. P. 141).

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 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 — butylphenol-formaldehyde resin modified with crushed 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 preparing the adhesive composition based on the remaining components.

An example of the preparation of the adhesive composition. Into the glue mixer containing the prepared glue composition as described above, which includes polychloroprene rubber Nairit NT, butylphenol formaldehyde resin 101K, thiuram, zinc oxide, magnesium oxide and an organic solvent, the calculated amount of the modified milled polycaproamide fiber is introduced, and the contents of the KHT mark are mixed with 5 K-5 10 minutes until smooth.

Get the adhesive composition 1-3, the compositions of which are shown in table 1.

The glue is a light beige color. 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 prototype when bonding vulcanized rubber based on butadiene nitrile rubber (SKN-18M) and chloroprene rubber (Neoprene A.C.) are given in table 2. For comparative tests, 3 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 a tensile testing machine МРС - 250 (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.

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 Neoprene AC according to the prototype is 1.77 MPa, and using modified crushed polycaproamide fiber grade 23 KNTS 2.5 MPa (composition 3).

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 can increase the strength when bonding products from vulcanized rubbers to each other, due to its participation in improving the adhesive properties of the adhesive.

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

Table 1 Components The content of components, parts by weight, in the composition one 2 3 Prototype Polychloroprene rubber Nairit NT one hundred one hundred one hundred one hundred Butylphenol formaldehyde resin 101K 90 90 90 90 Tiuram 2 2 2 2 Zinc oxide 5 5 5 5 Magnesium oxide 12 12 12 12 Organic solvent (a mixture of ethyl acetate and nefras in a percentage of 50:50) 800 800 800 800 Crushed polycaproamide fiber grade 23 KNTS - - - 5,0 Modified chopped polycaproamide fiber grade 23 KNTS 1,0 3.0 5,0 -

table 2 Shear Strength, MPa Substrate Type Metric for composition Prototype one 2 3 SKN-18M 0.93 0.92 0.81 0.78 Neoprene speaker 1.30 1.10 2,50 1.77

The technical and economic effect obtained from the use of the adhesive composition is that its use can significantly increase the strength when bonding vulcanized rubber to each other.

Claims (1)

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, milled polycaproamide fiber brand 23 KNTS, characterized in that it uses a modified fiberglass made from 23 KNTS fiberglass , previously obtained by treating a non-equilibrium low-temperature plasma of a glowing low-frequency discharge of alternating current in a vacuum chamber for 2 m chickpeas, with the following component ratio, mass parts .:
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 Modified chopped polycaproamide fiber grade 23 KNTS 1.0-5.0