RU2797809C2 - Method for producing a three-layer composite material based on ultra-high molecular weight polyethylene, rubber and metal - Google Patents

Abstract

FIELD: polymers.

SUBSTANCE: invention relates to polymer materials science with increased resistance to bending, abrasion, aggressive environments and can be used in the mining, automotive and bridge-building industries as structural and functional products operating under high loads. The use of this invention allows to expand the application and improve the quality of polymer products used in the mining and construction industries. A method for producing a three-layer composite material based on ultra-high molecular weight polyethylene, rubber compound and metal is described, moreover, a rubber compound based on isoprene rubber grade SKI-3 is used, characterized in that a surface layer is created based on ultra-high molecular weight polyethylene grade GUR-4022, for which it is preliminarily performed modification of polyethylene by introducing an interlayer adhesive interaction enhancer into the layer, which is used as diphenylguanidine, or captax, or tetramethylthiuram disulfide, at a mass ratio of components, wt.%: ultrahigh molecular weight polyethylene 98.0-99.5; modifier 0.5-2.0, the resulting modified ultra-high molecular weight polyethylene is sent for moulding in a cold press at a pressure of 10±0.3 MPa, where it is pressed for at least 5 minutes, a layer of rubber compound is placed on top of the moulded polyethylene and a base of steel grade 45, pre-treated with a thermosetting adhesive of the Chemosil 411 brand, the formed composite material package is pressed in a hot press at a pressing pressure of 10±0.3 MPa, pressing temperature 150-180°C, the unloading of the pressed product is performed after cooling in the press at a pressure of 10±0.3 MPa upon reaching a temperature of not more than 80°C.

EFFECT: obtaining a three-layer polymer-metal material with increased adhesive interaction between the layers.

1 cl, 1 dwg, 2 tbl

Description

The invention relates to the field of polymer materials science with increased resistance to bending, abrasion, aggressive environments and can be used in the mining, automotive and bridge-building industries as structural and functional products operating under high loads.

A known method of plasma-chemical modification of the rubber surface, which allows to obtain an anti-friction polymer protective coating, which reduces the coefficient of friction, increases wear resistance (see Friction and wear of plasma-chemically modified elastomers / E.F. Abdrashitov [et al.] // Friction and wear. - 2001. - T. 22. - No. 2. - S. 190-196). The application of a polymer compound to the rubber surface is carried out in a gaseous medium using a plasma glow discharge. Under the influence of plasma in a gaseous medium and on the surface layer of rubber, chemical reactions occur with the formation of a bound antifriction fluorocarbon coating. The formed film can be from several angstroms to micrometers thick, depending on the technological mode of sputtering.

The disadvantages of the known analogue include a complex technological process for obtaining a coating. Also, during operation, when the samples are stretched, the formation of cracks and peeling of the anti-friction protective coating are not excluded.

Also known is a method of ion-plasma spraying of metal-containing coatings on rubber to increase wear resistance, resistance to aggressive environments (see Technology for applying nanostructured metal coatings on rubber products / P.B. Grinberg [et al.] // Bulletin of Omsk University. - 2012. - No. 2 (64), pp. 249-252). The metal coating, carried out by the method of ion-plasma spraying, settles evenly on the surface of the elastomers. Rubbers coated with refractory metals have a higher wear resistance compared to the original ones. The increase in wear resistance occurs due to the fact that the coatings act as a solid lubricant.

The disadvantages of the analogue include a complex technological process for obtaining a coating. Also, during operation, when the samples are stretched, cracks form and the anti-friction protective coating peels off.

When creating a two-layer material based on ultra-high molecular weight polyethylene (UHMWPE) and elastomers, studies were carried out on the interaction of elastomers based on low-polarity rubbers, such as natural butadiene-methylstyrene grade SKMS-30, butadiene grade SKD and isoprene grade SKI-3 (see RU No. 2052357, class B32B 25/08, published 01/20/1996). In this case, the connection of UHMWPE with elastomers was carried out in the process of joint hot pressing.

The disadvantage of this solution is that the destruction during delamination occurs along the phase boundary, based on this, it can be assumed that the adhesive interaction between the layers is not high enough.

In addition, there is a known method for producing a two-layer material based on UHMWPE and elastomers (see RU No. 2072921, class B32B 25/08, publ. 10.02.1997), where studies were carried out on the effect of adsorption forces on the adhesion of elastomers with UHMWPE containing fine fillers - chalk, kaolin and tuff. It was found in the work that the bond strength of elastomers with UHMWPE during delamination varied from 101 to 114 N/cm ² depending on the filler, only in the sample where UHMWPE is filled with 0.3 wt.% chalk, destruction occurs along the rubber.

The disadvantage of the known solutions lies in the fact that the destruction during delamination occurs as a whole along the phase boundary, which indicates insufficient strength of the adhesive interaction between the layers.

The closest in technical essence is a method for producing a two-layer material based on UHMWPE brand GUR 4120 with a molecular weight of 5 million and industrially produced rubber compound V-14 based on nitrile rubber brand BNKS-18 filled with ultra-high molecular weight polyethylene brand GUR 4120 (see RU No. 2615416, class C08C 4/00, C08L 33/18, C08K 5/01, B32B 25/16, published 03.03.2017).

The disadvantages of the known technical solution are the low adhesive strength between UHMWPE and the elastomer, the complexity and cost of the manufacturing process due to the additional introduction of UHMWPE into the elastomer, as well as the low bending resistance of the material.

The task to be solved by the claimed solution is to create a new composite material for structural purposes based on ultra-high molecular weight polyethylene, rubber and metal.

The technical effect obtained in solving the problem is expressed in obtaining a three-layer polymer-metal material with increased adhesive interaction between the layers.

To solve the problem, the method for producing a three-layer composite material based on ultra-high molecular weight polyethylene, rubber and metal is characterized by the fact that a surface layer of material is created based on ultra-high molecular weight polyethylene of the GUR-4022 brand, for which, the modification of polyethylene is preliminarily performed by introducing an interlayer adhesive interaction enhancer into the polyethylene layer , which is used as diphenylguanidine or captax or tetramethylthiuram disulfide, with a mass ratio of components, wt.%: ultra-high molecular weight polyethylene - 98.0-99.5; modifier - 0.5-2.0, the resulting modified polyethylene is sent for molding into a cold press at a pressure of 10 ± 0.3 MPa, where it is pressed for at least 5 minutes, after which, a layer of rubber mixture based on isoprene is placed on top of the molded polyethylene. rubber grade SKI-3 and a metal base is applied to the rubber layer, pre-treated with a thermosetting adhesive designed for gluing rubbers on a metal surface, for example, with Chemosil 411 glue, then the formed composite material package is pressed in a hot press at a specific pressing pressure of 10 ± 0 .3 MPa, pressing temperature 150-180°C, while the duration of pressing depends on the technical conditions, in the final stage, the unloading of the pressed finished product is performed after cooling in the press at a pressure of 10 ± 0.3 MPa when the material temperature reaches no more than 80° C.

Comparative analysis of the features of the claimed solution with known features indicates the compliance of the claimed solution with the criterion of "novelty".

The totality of the features of the invention provides a solution to the claimed technical problem, namely, increasing the reliability of the details of the nodes with damping properties and structural strength, resistance to abrasion, exposure to hydrocarbon media.

It is known that when diphnylguanidine (DPG) is introduced into the rubber compound, a strong connection of UHMWPE with elastomers occurs due to the appearance of chemical bonds at the interface (see Study of the effect of diphenylguanidine on the adhesive interaction of elastomers with ultra-high molecular weight polyethylene / A.A. Dyakonov [et al. ] // Siberian Federal University. Technics and technologies. - 2019. - No. 4 (12). - P. 476-487). The addition of DPG to the rubber compound makes it possible to produce two-layer materials based on UHMWPE and rubber with a bond strength exceeding the cohesive strength of rubber. From which it follows that the increase in adhesive interaction between UHMWPE and rubber is influenced by standard vulcanization accelerators.

In addition, it is known that in the process of vulcanization it is possible to form a strong adhesive bond between rubber and metal by means of hot fastening due to the appearance of chemical bonds at the interface (see Fastening to metal of filled and unfilled rubbers based on a combination of rubbers with binders of the "CHEMOSIL" group / A. B. Vetoshkin [et al.] // Proceedings of higher educational institutions. Series: Chemistry and chemical technology. - 2006. - V. 49. - No. 10. - P. 74-77; Adhesives for a reusable space system / A.P. Petrova [et al.] // Aviation Materials and Technologies - 2013. - No. 1. - P. 131-136). This method is widely used due to its technological simplicity, ensuring the dynamic and thermal stability of products.

The claimed technical solution is illustrated by a drawing, where the figure shows the layout of the composite material layers: A - UHMWPE layer, B - rubber layer, C - metal base layer.

The invention proposes a method for creating a three-layer composite material based on UHMWPE, elastomer and metal. The new material should mainly have high wear resistance and structural strength. UHMWPE performs the protective function of rubber, preventing premature abrasion and exposure to aggressive hydrocarbon media, the rubber layer performs damping properties, the metal component performs a frame function (see drawing). The combination of the unique properties of UHMWPE, elastomers and metals makes it possible to create products with increased wear resistance, aggressive resistance, damping properties and carcass strength.

In the claimed technical solution, the fastening of UHMWPE, elastomer and metal is carried out simultaneously in the process of joint hot pressing, which simplifies the technological process and promotes the formation of a strong connection between materials.

The process of creating a three-layer composite material is carried out in 5 stages:

- molding the modified UHMWPE powder in a mold under a pressure of 10 MPa for 5 min;

- laying the rubber mixture on top of the molded UHMWPE powder;

- laying the metal on the rubber layer, moreover, the metal surface is pre-treated with a special glue;

- hot pressing in a vulcanizing press molds with UHMWPE, rubber compound and metal; pressing temperature 150-180°C, pressing time is set depending on the technical conditions;

- cooling of the pressed material in a press under a pressure of 10 MPa until a temperature of no more than 80°C is reached.

For experimental work on the creation of a new three-layer composite material, steel grade 45 was used, as rubber - an elastomer based on rubber SKI-3, polyethylene - UHMWPE brand Ticona GUR-4022 with a molecular weight of 5.3 × 10 ⁶ g/mol. In this case, the connection of rubber to metal was carried out using Chemosil 411 glue.

To increase the strength of the adhesive bond between the layers of elastomer and UHMWPE, modifying additives of DPG (option 1), captax (option 2), and tetramethylthiuram disulfide (TMTD, option 3) were introduced into the polyethylene layer. The composition of the compositions is shown in table 1.

The adhesion between rubber and UHMWPE coating was assessed by the magnitude of the force required to separate the layers from each other, for which we used the technique described in GOST 6768-75 “Method for determining the bond strength between layers during delamination”.

The test specimens had the shape of a rectangular parallelepiped with a width of (25.0 ± 1.0) mm, a thickness of (6.0 ± 0.5) mm and a length of (80.0 ± 1.0) mm. Testing was carried out on a universal testing machine Autograph AGS-JSTD (Shimadzu, Japan), providing a moving clamp travel speed of 50 ± 5 mm/min. Determination of adhesion between metal and rubber was carried out in accordance with GOST 411-77. At the same time, at least 3 samples were taken from each batch. Table 2 shows the results of a study of adhesion between rubber based on SKI-3 rubber and UHMWPE filled with DPG (option 1), Captax (option 2) and TMTD (option 3), and between rubber and metal.

The results of experimental studies show that the introduction of DPG or Captax or TMTD into the UHMWPE layer leads to an increase in the strength of the adhesive joint between the UHMWPE layers and the elastomer by 2.2-8.1 times compared to the prototype. At the same time, the adhesion between the surface of the steel sheet and the rubber is also at a high level, which satisfies the operational requirements.

Table 1

The composition of the compositions

No. Compound UHMWPE DFG captax TMTD 1 99.5 0.5 - - 2 99.5 - 0.5 - 3 99.5 - - 0.5 4 99 1 - - 5 99 - 1 - 6 99 - - 1 7 98 2 - - 8 98 - 2 - 9 98 - - 2

table 2

Results of the study of adhesion between UHMWPE, elastomer and metal

Layer 1 Layer 2 / Layer 3 Adhesion, N The nature of the destruction Rubber UHMWPE+0.5DFG 292 Rubber failure Rubber UHMWPE+1DFG 353 Rubber failure Rubber UHMWPE+2DFG 490 Rubber failure Rubber UHMWPE+0.5 captax 317 Rubber failure Rubber UHMWPE+1 Captax 378 Rubber failure Rubber UHMWPE+2 Captax 184 Rubber failure Rubber UHMWPE+0.5 TMTD 672 Rubber failure Rubber UHMWPE+1 TMTD 670 Rubber failure Rubber UHMWPE+2 TMTD 665 Rubber failure Prototype Rubber V-14+UHMWPE UHMWPE 83 - Rubber Steel grade 45 243 Rubber failure

Claims (1)

A method for producing a three-layer composite material based on ultra-high molecular weight polyethylene, a rubber compound and metal, moreover, a rubber compound based on isoprene rubber grade SKI-3 is used, characterized in that a surface layer is created based on ultra-high molecular weight polyethylene grade GUR-4022, for which polyethylene is preliminarily modified by introducing into the layer an interlayer adhesive interaction enhancer, which is used as diphenylguanidine, or captax, or tetramethylthiuram disulfide, at a mass ratio of components, wt.%: ultra-high molecular weight polyethylene 98.0-99.5; modifier 0.5-2.0, the resulting modified ultra-high molecular weight polyethylene is sent for molding in a cold press at a pressure of 10 ± 0.3 MPa, where it is pressed for at least 5 minutes, a layer of rubber mixture and a base of steel grade 45 are placed on top of the molded polyethylene , pre-treated with Chemosil 411 thermosetting adhesive, the formed composite material package is pressed in a hot press at a pressing pressure of 10 ± 0.3 MPa, a pressing temperature of 150-180 ° C, the pressed product is unloaded after cooling in a press at a pressure of 10 ± 0.3 MPa when the temperature reaches not more than 80°C.

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