RU2515784C2 - Composition based on copolymer of fluorolefin and perfluoroalkylvinyl ethers, containing nitrile groups - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to obtaining polymer compositions based on copolymers of fluorolefins, applied in chemical, oil-refining industry, in particular in units of deep drilling equipment. Composition contains copolymer of fluorolefin (tetrafluoroethylene or vinylidenfluoride) and perfluoroalkylvinyl ethers, which contains nitrile groups, vulcanising agent bis-4,4'-dioxy-3,3'-diaminodiphenyl hexafluoropropane and fullerene soot.

EFFECT: products obtained on the base of said composition (vulcanisates) possess higher tension in 100% stretching with preservation of all other physicomechanical properties.

2 tbl, 1 ex

Description

The proposed composition relates to the field of production of compositions based on ternary or quaternary copolymers of tetrafluoroethylene (TFE) or vinylidene fluoride (VF) with perfluoroalkyl vinyl ethers (PFAVE), one or more of which contains nitrile groups.

Such compositions are intended for use in the chemical oil and oil refining industries, in particular in the nodes of deep drilling technology, where one of the most important physical and mechanical characteristics is stress at 100% tension. A known composition based on copolymers of vinylidene fluoride and perfluoroalkyl vinyl ethers of the general formula:

Where

a = 74.8-75.3

b = 23.7

s = 1.0-1.5

including as a vulcanizing agent bisaminophenol in an amount of 2 masses. parts, and as a filler - carbon black brand N-990 in an amount of 40 parts by weight per 100 parts by weight copolymer. Vulcanizates based on such a composition have good chemical resistance and frost resistance. One of the main disadvantages is the very low value of stress at 100% tension, which limits the scope of their application. Even with the introduction of a filler in an amount of 40 parts by weight this indicator is only 4.3 ÷ 4.2 MPa (US Pat. USA 6294627, C08F 116/12, prior dated 05/18/1999). Moreover, the vulcanizates have low physical and mechanical properties (conditional strength does not exceed 5.2 MPa, and the relative elongation is ≈110%). With the introduction of filler in the amount of 20-25 oils, these properties are further reduced. So, the stress index at 100% tension will be about 2.0 ~ 2.2 MPa.

A known composition based on a triple or quaternary copolymer of tetrafluoroethylene, perfluoromethylvinyl ether and perfluoroalkylvinyl ethers containing a nitrile group, comprising, as a vulcanizing agent, perfluorodiidiidoylamidines of the formula

in the amount of 1-4 mass. Hours per 100 mass. C. copolymer.

The composition may contain a filler, which is used, for example, carbon black brand N 990, Aerosil (Pat. Ru 2319717, C08L 27/18, prior. 07/10/2006). Most of the physical and mechanical properties of the vulcanizates of such a composition are at a high level. However, the stress index at 100% elongation is not high enough. So for unfilled compositions it is 2.2 ÷ 3.1 MPa, and for filled 6.6-10.6 MPa.

The closest analogue in technical essence is a composition based on a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ethers of the general formula

Where

n = 42-70 mol%

m = 25-55 mol%

p = ... 1-4 mol%.

a = 1 -7 mol%,

including a vulcanizing agent bis 4,4'-dioxi-3,3'-diaminodiphenylhexafluoropropane (BOAF) in an amount of 1.5 parts by weight and filler (carbon black P-701) in an amount of 25 parts by weight per 100 parts by weight copolymer.

Vulcanizates based on such a composition are well processed on standard equipment and have good physical and mechanical properties. However, as in the previously mentioned analogues, the stress index at 100% elongation for unfilled vulcanizates is 1.5-1.8 MPa, and for filled it does not exceed 10.5 MPa.

The objective of the proposed technical solution is to develop compositions based on copolymers of both vinylidene fluoride and tetrafluoroethylene with perfluoroalkyl vinyl ethers containing nitrile groups, which have an increased stress at 100% tension while maintaining the remaining physical and mechanical properties.

The problem is achieved in that the composition based on copolymers of fluoroolefins and perfluoroalkyl vinyl ethers containing nitrile groups, including a curing agent - bis 4,4'-dioxo-3,3'-diaminodiphenylhexafluoropropane, additionally contains fullerene soot in the following ratio of components, masses. hours:

copolymer one hundred curing agent 1 + 2 soot fullerene 0.5-2

As the basis of the composition, triple or quaternary copolymers of VF or TFE with perfluoroalkyl vinyl ethers containing nitrile groups are used, for example, copolymers of the following structural formulas:

The composition may contain a filler, for example carbon black brand T-900, P-701, which are industrial products. The fullerene soot used to obtain the composition is produced in accordance with TU 2166-004-65523364-2010 (fullerene content 9-14% by weight).

Typically, the filler is administered in an amount of 20-25 parts by weight per 100 parts by weight copolymer. The composition is prepared by mixing the components in closed-type rubber mixers or on rollers at a temperature of 20-25 ° C. First, polymer, fullerene soot is fed, and, if necessary, carbon black, and then a curing agent.

Vulcanization is carried out in two stages, first in the press at 150-180 ° C for 30 minutes, and then in a thermostat with a stepwise rise in temperature from 30 ° C to 230 ~ 280 ° C for 28-40 hours.

The assessment of physical and mechanical properties is carried out according to the following GOSTs:

Elastic strength indicators - in accordance with GOST 270-75

Shore hardness - according to GOST 263-75.

Accumulation of relative residual compression deformation at 250, 275 ° С for 24 hours at 20% compression - according to GOST 9.029-74.

The following are examples illustrating the invention.

Example 1

On rollers at a roll temperature of 25 ° C, 100 mass parts of a copolymer of formula Ш are mixed, where n = 42.6 mol%, m = 54.6 mol%, p = 2.4 mol%, and = 0.4 mol% 1.0 mass. including fullerene soot and 1 mass. including vulcanizing agent (BOAF) for 10 minutes The resulting mixture was subjected to vulcanization, first in a press at 180 ° C for 30 minutes, and then in a thermostat for 40 hours at 230 ° C.

For ease of review, the compositions of example 1 and all subsequent examples are summarized in table 1, control examples are also shown there (without adding fullerene soot).

The test results of the obtained vulcanizates are shown in table 2.

As can be seen from the data given in the table, the introduction of fullerene soot in the composition

based on copolymers of vinylidene fluoride or tetrafluoroethylene with perfluoroalkylvinyl ethers containing nitrile groups, it is possible to obtain compositions with an increased stress index at 100% tension, while maintaining other physical and mechanical properties.

Claims (1)

A composition based on a copolymer (s) of fluoroolefin and perfluoroalkylvinyl ethers containing nitrile groups, comprising bis-4,4'-dioxo-3,3'-diaminodiphenylhexafluoropropane as a curing agent, the copolymer comprising vinylidene fluoride or tetrafluorine as a fluoroolefin and the composition further comprises fullerene soot in the following ratio of components, parts by weight:
copolymer one hundred curing agent 1-2 fullerene soot 0.5-2