RU2540307C1 - Anaerobic sealing composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to field of anaerobic sealing compositions based on (meth)acryl monomers, applied as gasket in sealing flanges and flat joints, made of various metals and alloys, in particular applied in butt end sealing of pumps, steering units, units of thrust reverse systems and other hydrosystems of airplanes. Anaerobic sealing composition contains, wt. p.: (meth)acryl monomer 20.0-55.0, initiator 2.0-5.1, inhibitor 0.05-0.1, functional additives 4.0-20.0 and mixture, containing 93-80 wt % of product of interaction of hydroxyl-containing polybutadiene rubber SKD-GTRA, aromatic and/or aliphatic diisocyanate, hydroxyl-containing (meth)acrylate and water with their molar ratio respectively (1-5):(2-6):2:(0.001-0.1) and 7-20 wt % of product of interaction of hydroxyl-containing (meth)acrylate, water and 2,4-toluylenediisicyanate with their molar ratio 2:(0.001-0.1):1 - 80.0-45.0.

EFFECT: preservation of adhesive strength of hardened anaerobic sealing composition in exploitation of products in medium of hydraulic liquid based on phosphoric acid ethers with achievement of required rate of hardening and limit of adhesion tearing strength.

1 tbl, 18 ex

Description

The present invention relates to the field of anaerobic sealing compositions based on (meth) acrylic monomers.

The developed anaerobic composition is used as a gasket for sealing flanges and flat joints made of various metals and alloys. The sealing effect is achieved by curing the composition in the gap between the joined surfaces and the formation of the gasket in place. This technology is used in many engineering industries. The inventive anaerobic composition is supposed to be used in mechanical seals of pumps, steering units, units of traction reversal systems and other aircraft hydraulic systems.

Currently, domestic manufacturers of aircraft hydraulic systems put forward the following requirements for anaerobic sealing compositions:

- high curing rate (set of 50% strength in no more than 3 hours at 20-25 ° C);

- adhesive strength in the range of 6-16 MPa;

- a decrease in adhesive strength after exposure to hydraulic fluid at 90 ° C for 90 days is not more than 10%.

The required curing rate of the anaerobic composition allows to intensify the assembly process. The adhesive strength at separation of 6-16 MPa is optimal, since lower strength does not provide sufficient tightness, and large makes it difficult to dismantle the structure if necessary.

The authors of the invention were faced with the task of developing an anaerobic sealing composition that would provide the required cure speed of the composition, the adhesive strength at break and maintaining this adhesive strength when operating the products in a medium of hydraulic fluids based on phosphoric acid esters, for example, NGZh-5U, Skaydrol 500V-4 , LD-4, Hyget-1U-A, etc.

Known anaerobic curable composition for sealing flange joints (EP 064672, 1995), containing 65-40 wt.h. mixtures of aliphatic urethane acrylates with a molecular weight of 3000-10000 and a molecular weight of 1000-3000, 35-60 wt.h. phenyl substituted monoacrylate, as well as accelerators, stabilizers and functional additives.

This composition in the cured state has high elasticity (elongation at break of at least 80%), retains its properties when exposed to temperatures up to 150 ° C in an environment of oils, glycols for 7 days.

We reproduced a composition consisting of 40 parts by weight oligoureth-nacrylate with a molecular weight of 4800, obtained by the interaction of a polyester with a molecular weight of 2000, aliphatic (hexamethylene) diisocyanate and hydroxypropylmethacrylate, taken in a molar ratio of 2: 3: 2, 20 wt.h. oligourethane acrylate with a molecular weight of 2600, obtained by reacting a polyester with a molecular weight of 2000, aliphatic (hexamethylene) diisocyanate and hydroxylpropyl methacrylate, taken in a ratio of 1: 2: 2, 40 parts by weight phenoxyethyl acrylate to which curing initiators and stabilizers are added.

The test results of samples glued with this composition and kept in NGZh-5U liquid at 90 ° C for 1 month already showed that the adhesion strength at separation is significantly reduced and is less than 50% of the initial strength, which significantly limits the life of the products in the environment hydraulic fluids.

Also known anaerobic sealing composition (US 6673875, 2004), including:

di- or three (meth) acrylic monomer 5-30 wt.%

the product of the interaction of hydroxyl-containing (meth) acrylate, aromatic or cycloaliphatic isocyanate and acrylonitrile butadiene rubber 5-75 wt.%

the product of the interaction of polyisocyanate and (meth) acrylate with hydroxyl groups of 20-50 wt.%.

The composition also contains initiators, stabilizers and other functional additives.

This composition has a high toughness and resistance to cracking. The composition according to the patent after curing at 25 ° C for 24 hours has a shear strength of 2037-2450 p.s.i. (14-17 MPa), and after additional heating at 90 ° C for 2 hours 4042-6800 p.s.i. (28-48 MPa). This suggests that the composition at 25 ° C in 24 hours is cured by 35-50%. Thus, the composition has a low polymerization rate at 25 ° C and therefore will not provide a set of 50% strength in 3 hours. In addition, the composition has high strength, which makes it impossible to dismantle the compounds, for example for repair.

The prototype of the invention is an anaerobic sealing composition based on a reactive mixture containing 28-96 parts by weight methacrylic monomer, 72-4 parts by weight urethane acrylate - the product of the interaction of oligodiol, 2,4-toluene diisocyanate, hydroxyl-containing (meth) acrylate and water with their molar ratio (1-8): 2: (2-9) :( 0.001-0.1), 4.0-11 5 parts by weight initiator, 0.025-0.1 parts by weight inhibitor and 6.7-87.5 parts by weight functional additives (fillers, thickeners, plasticizers, dyes, etc. (RU 2374290, 2009).

The composition of the prototype has a high curing speed (after 1 hour at 20-25 ° C, 70-100% of strength is achieved), optimal strength characteristics (7-10 MPa after 24 hours), ensures tightness of the flange connection at a pressure of 0.6 MPa after 45 minutes after application. However, tests to determine the performance of the composition in contact with hydraulic fluids showed that the strength of glued samples drops by 50% at 3-month exposure in the medium of NGZH-5U at 20-25 ° C and by 75% during exposure in the medium of NGZhU-5U at 90 ° C for 90 days, which is its serious drawback.

The technical result of the invention is to maintain the adhesive strength of the cured anaerobic sealant composition when operating the products in a hydraulic fluid based on phosphoric acid esters when the required composition cure rate and the adhesion tensile strength are reached.

To achieve the technical result, an anaerobic sealing composition based on a reactive mixture of (meth) acrylic monomer and oligourethane acrylate, including initiator, inhibitor and functional additives, contains oligourethane acrylate as a mixture of the product of the interaction of hydroxyl-containing polybutadiene rubber SKD-GTPA, aromatic or aliphatic diisocis (hydroxy-diisocis ) acrylate and water at their molar ratio, respectively (1-5) :( 2-6): 2: (0.001-0.1) and the hydro silsoderzhaschego (meth) acrylate, water and 2,4-tolylene diisocyanate at molar ratio of 2: (0.001-0.1): 1, with the following component ratio of the composition, in parts by weight .:

(meth) acrylic monomer 20.0-55.0 a mixture of 93-80 wt. % product of the interaction of hydroxyl-containing polybutadiene rubber SKD-GTPA, aromatic and / or aliphatic diisocyanate, hydroxyl-containing (meth) acrylate and water and 7-20 wt. % the product of the interaction of hydroxyl-containing (meth) acrylate, water and 2,4-toluene diisocyanate 80.0-45.0 initiator 2.0-5.1 inhibitor 0.05-0.1 functional additives 4.0-20.0

Phenoxyethyl (meth) acrylate, (meth) propylene glycol, disobornyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, etc. are used as (meth) acrylic monomers.

The initiating system includes hydroperoxides, tertiary aromatic and aliphatic amines, organic sulfimides, hydrazines, for example cumyl hydroperoxide (HPA), tertiary butyl hydroperoxide (GPTB), dimethyl paratoluidine (DMPT), orthobenzosulfimide (BSI), acetylphenyl phenyl.

Quinones, stable nitroxyl radicals, complexones, substituted phenols, for example 2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl (nitroxin-1), naphthoquinone, hydroquinone, Trilon B, etc. are used in the inhibitory system.

Functional additives include fillers, thickeners, plasticizers, dyes, and other substances.

As diisocyanates, 2,4-toluene diisocyanate (TDP), isophorondiisocyanate (IPDI), hexamethylene diisocyanate (HMDI), etc. can be used.

As the hydroxyl-containing (meth) acrylate, hydroxyethyl methacrylate (MEG), hydroxypropyl methacrylate (MHP), hydroxypropyl acrylate (APG), etc. can be used.

Upon receipt of urethane acrylate use hydroxyl-containing polybutadiene rubber (TU 38.103315-86).

The following are examples of specific embodiments of the invention, illustrating its essence.

Example 1

The method of obtaining the product of the interaction of hydroxyl-containing polybutadiene rubber SKD-GTPA, 2,4-toluene diisocyanate, hydroxyethyl methacrylate and water with a molar ratio of 5: 6: 2: 0.1 (product A).

100.0 parts by weight (0.053 mol) of SKD-GTPA rubber (m. M. 1880) are loaded into the reactor and 11.1 parts by weight are metered with stirring at a temperature of 45-50 ° C. (0.064 mol) 2,4-toluene diisocyanate (TDI). Stirring is continued at 70-75 ° C for 4-5 hours until the content of isocyanate groups reaches ~ 0.8%. Then, 2.76 wt.h. (0.021 mol) of hydroxyethyl methacrylate (MEG) containing 0.019 parts by weight (0.001 mol) of water and 0.058 wt.h, the catalyst was dibutyl dicaprylate tin (DOC). At the end of the dosage, the reaction mass is maintained at a temperature of 70-75 ° C for 4-5 hours until the isocyanate groups disappear (according to the IR spectrum). The finished product is a viscous mass of light brown.

Example 2

The method of obtaining the product of the interaction of hydroxyl-containing polybutadiene rubber SKD-GTPA, isophorondiisocyanate, hydroxypropyl methacrylate and water with a molar ratio of 1: 2: 2: 0.05 (product B).

100.0 parts by weight are charged to the reactor. (0.053 mol) of rubber SKD-GTRA (m.m. 1880) containing 0.05 parts by weight (0.0027 mol) of water and at a temperature of 45-50 ° C with stirring dose of 23.53 wt.h. (0.106 mol) of isophorondiisocyanate (IPDI). Stirring is continued at 70-75 ° C for 7 hours. Then add 0.2 wt.h. DOC and stirred for 3-4 hours to reach the content of isocyanate groups of 3.61%. Next, for 3-4 hours, 15.26 wt.h. (0.106 mol) of hydroxypropyl methacrylate (PGM) containing 0.039 parts by weight DOC. At the end of the dosage, the reaction mass is maintained at a temperature of 70-75 ° C for 4-5 hours until the isocyanate groups disappear (according to the IR spectrum). The finished product is a viscous mass of light brown.

Example 3

The method of obtaining the product of the interaction of hydroxyl-containing polybutadiene rubber SKD-GTPA, isophorondiisocyanate, hydroxy-propyl acrylate and water at a molar ratio of 2: 3: 2: 0.001 (product B).

100.0 parts by weight are charged to the reactor. (0.053 mol) of rubber SKD-GTRA (m.m. 1880) and at a temperature of 45-50 ° C with stirring, 17.76 parts by weight are metered. (0.08 mol) IFDI. Stirring is continued at 70-75 ° C for 7 hours. Then add 0.03 wt.h. DOC and stirred for 3-4 hours until the content of isocyanate groups reaches ~ 1.9%. Next, for 3-4 hours, 6.89 parts by weight are dosed. (0.053 mol) of hydroxypropyl acrylate (APG) containing 0.018 parts by weight (0.001 mol) of water and 0.032 parts by weight DOC. At the end of the dosage, the reaction mass is maintained at a temperature of 70-75 ° C for 4-5 hours until the isocyanate groups disappear (according to the IR spectrum). The finished product is a viscous mass of brown.

Example 4

A method of obtaining a product of the interaction of hydroxypropyl acrylate, water and 2,4-toluene diisocyanate with a molar ratio of 2: 0.001: 1 (product D).

100.0 parts by weight are charged to the reactor. (0.77 mol) APG containing 0.007 wt.h. (0.0004 mol) of water and 0.08 wt.h. DLC and at a temperature of 40-45 ° C with stirring, dose of 67.0 wt.h. (0.385 mol) TDI at such a rate that the temperature of the reaction mass does not exceed 40-45 ° C. At the end of the dosage, the reaction mass is kept at a temperature of 50-55 ° C for 4-5 hours until the isocyanate groups disappear (according to the IR spectrum).

The finished product is a viscous colorless viscous mass.

Example 5

A method of obtaining a product of the interaction of hydroxypropyl acrylate, water and 2,4-toluene diisocyanate with a molar ratio of 2: 0.1: 1 (product D).

100.0 parts by weight are charged to the reactor. (0.69 mol) of PGM containing 0.6 wt.h. (0.0345 mol) of water and 0.08 wt.h. DOC and at a temperature of 40-45 ° C with stirring, dose 60.0 wt.h. (0.345 mol) TDI at such a rate that the temperature of the reaction mass does not exceed 40-45 ° C. At the end of the dosage, the reaction mass is kept at a temperature of 50-55 ° C for 4-5 hours until the isocyanate groups disappear (according to the IR spectrum). The finished product is a viscous colorless viscous mass.

The following are examples of the preparation and testing of the inventive anaerobic sealant composition.

Example 6

An anaerobic sealing composition is prepared by mixing in a glass reactor 42.0 wt.h. phenoxyethyl acrylate (PEA), 3.0 parts by weight of PGM, 55.0 parts by weight of interaction products consisting of a mixture of 34.1 wt.h. product A and 17.05 parts by weight product B (93 wt.%), and 3.85 wt.h. product D (7 wt.%), 2 wt.h. cumyl hydroperoxide (GPC), 0.8 wt.h. o-benzosulfimide (BSI), 0.4 wt.h. acetylphenylhydrazine (AFH), 0.057 parts by weight disodium salt of ethylenediamine-N, N, N ′, N′-tetraacetic acid (Trilon B), 0.003 parts by weight oxalic acid, 0.04 parts by weight 2,2,6,6-tetramethyl-4-oxo-piperedin-1-oxyl (nitroxyl-1), 0.07 parts by weight dye organic fat-soluble dark red W and 10.0 wt.h. aerosil. The tests are carried out as follows.

The tensile strength at separation is determined according to GOST 14760-69 after 24 hours (δ ₂₄ ) on a testing machine at a moving gripping speed of 20 mm / min (GOST 28840-90). The curing rate is determined by the set time of 50% of the final strength δ ₂₄ . Efficiency in the environment of hydraulic fluids is determined by the change in the tensile strength at separation after exposure of the samples for 90 days in a liquid НЖЖ-5У at 90 ° C (δ _нжж ) compared to the initial strength δ ₂₄ .

The composition and results of its tests are shown in the table.

Example 7

An anaerobic sealing composition is prepared by mixing in a glass reactor 41.0 wt.h. phenoxyethyl methacrylate (FEM), 14.0 parts by weight of APH, 45.0 parts by weight interaction products consisting of 39.0 parts by weight product B (87 wt.%) and 6.0 wt.h. product G (13 wt.%), 2.7 wt.h. HPA, 1.4 parts by weight BSI, 1.0 parts by weight dimethyl-n-toluidine (DMPT), 0.005 parts by weight naphthoquinone, 0.02 parts by weight Trilon B, 0.04 parts by weight nitroxyl-1, 10.0 parts by weight powdered fluoroplast-4 (F-4), 2.5 parts by weight polyoxyethylene ether isooctyl phthalate (OP-7), 0.01 wt.h. dye fat-soluble bright blue anthrachine and 2.0 wt.h. aerosil.

The composition and results of its tests are shown in the table.

Example 8

An anaerobic sealing composition is prepared by mixing in a glass reactor 5.0 wt.h. isobornyl acrylate (IBA), 10.0 parts by weight FEA, 5.0 parts by weight MEG, 80.0 parts by weight interaction products consisting of a mixture of 66.4 wt.h. product A (83 wt.%) and 13.6 wt.h. product G (17 wt.%), 3.5 wt.h. HPA, 1.0 wt.h. BSI, 0.4 parts by weight AFG, 0.005 parts by weight hydroquinone, 0.015 parts by weight 4.4′-bis (dimethylamino) triphenylmethanoxalate (malachite green), 0.03 parts by weight nitroxyl-1, 0.01 wt.h. dye organic fat-soluble green anthrachine, 5.0 wt.h. dioctyl phthalate (DOP) and 5.0 wt.h. aerosil.

The composition and results of its tests are shown in the table.

Example 9

An anaerobic sealing composition is prepared by mixing in a glass reactor 31.5 parts by weight of FEM, 4.5 parts by weight PGM, 64.0 parts by weight interaction products consisting of a mixture of 51.2 wt.h. product B (80 wt.%) and 12.8 wt.h. product D (20 wt.%), 1.2 wt.h. tert-butyl hydroperoxide (GPTB), 0.5 parts by weight dibenzosulfimide (DBSI), 0.3 parts by weight AFG, 0.008 parts by weight ionol, 0.02 parts by weight Trilon B, 0.02 parts by weight nitroxyl-1, 10.0 parts by weight triallyl isocyanurate (TAIC), 5.0 parts by weight polypropylene glycol adipate dibutyl ether (PDEA-4) and 5.0 parts by weight of aerosil.

The composition and results of its tests are shown in the table.

Example 10

An anaerobic sealing composition is prepared by mixing in a glass reactor 6.0 wt.h. tetrahydrofurfuryl methacrylate (THFM), 19.0 parts by weight FEM, 3.0 parts by weight MEG, 72.0 parts by weight of interaction products consisting of a mixture of 46.3 parts by weight product A and 20.0 parts by weight product B (92 wt.%), as well as 5.7 wt.h. product G (8 wt.%), 2 wt.h. GPC, 0.8 parts by weight BSI, 0.6 parts by weight DMPT, 0.015 parts by weight hydroquinone, 0.02 parts by weight malachite green, 0.03 parts by weight nitroxyl-1 and 4.0 parts by weight aerosil.

The composition and results of its tests are shown in the table.

Examples 11-18 (for comparison)

Methods of preparation and test methods of example 1. The composition and their properties are shown in the table.

From the data given in the table it can be seen that for the claimed composition, the adhesion strength at break after 24 hours is 7.1-14.9 MPa, the set time of 50% strength does not exceed 3 hours (see examples No. 1-10). The inventive composition is operable in an environment of hydraulic fluids based on phosphoric acid esters (for example, NGZH-5U), the adhesive strength at break after testing in a hydraulic fluid NGZH-5U is 92-105% of the original (δ ₂₄ ) (see examples No. 1 -10), which significantly exceeds the performance of the prototype.

The composition of the prototype has a tensile strength at separation (δ ₂₄ ) equal to 7.0-10 MPa, a set of 50% strength is carried out in less than 1 hour, however, the residual strength after exposure to NGZH-5U is 1.7-2.5 MPa (25% of δ ₂₄ ), which indicates the low efficiency of the composition in this environment (see example No. 11).

A distinctive feature of the claimed composition in comparison with the prototype is the use as a urethane acrylate of a mixture of the product of the interaction of hydroxyl-containing polybutadiene rubber SKD-GTPA, aromatic and / or aliphatic diisocyanate, hydroxyl-containing (meth) acrylate and water and the product of the interaction of hydroxyl-containing (meth) acrylate, water and 2, 4-toluene diisocyanate in an amount of 45-80 parts by weight 20-55 parts by weight (meth) acrylic monomer.

Examples No. 12-13 show that when using the specified mixture in the composition in amounts outside the claimed, it leads to a decrease in the curing rate (set time 50% δ ₂₄ ) and to a loss in the performance of the composition in the medium of the hydraulic fluid НЖЖ-5У. The use in the composition of the products of the interaction in amounts other than those claimed also leads to a deterioration in the performance of the compositions in the medium of hydraulic fluids. When using as an oligourethane acrylate an interaction product based on SKD-GTPA in an amount of more than 93 wt. % and the interaction product based on TDI in an amount of less than 7 wt. % (see example No. 14) leads to a decrease in strength characteristics (δ ₂₄ ), curing rate and loss of performance in the environment of hydraulic fluids. The use of an interaction product based on SKD-GTPA as an oligourethane acrylate in an amount of less than 80 wt. % and the interaction product based on TDI in an amount of more than 20 wt. % (see example No. 15) leads to an increase in the strength characteristics (δ ₂₄ ) above the permissible limit, a decrease in the curing rate and a loss of working capacity in the environment of hydraulic fluids.

Compositions not containing in their composition the inventive mixture of interaction products (see example No. 16) do not meet the requirements for strength characteristics, curing speed and performance in the environment of hydraulic fluids.

Examples No. 17 and No. 18 show that the use of not a mixture of interaction products in the composition, but only an interaction product based on SKD-GRA (see example No. 18) or only an interaction product based on TDI (see example No. 17) impairs strength characteristics, curing speed and does not allow to improve the performance of the compositions in the environment of hydraulic fluids. The adhesive strength of such compositions after testing falls and is 31-43% of the original (see examples No. 17-18 in comparison with example No. 9).

As a result of the interaction of hydroxyl-containing polybutadiene rubber SKD-GTPA, aromatic and / or aliphatic diisocyanate, hydroxyl-containing (meth) acrylate, water and hydroxyl-containing (meth) acrylate, water, 2,4-toluene diisocyanate, polymerizable oligomers are formed, which together with other ingredients of the proposed composition provide the necessary curing speed and optimal consumer properties of the cured gasket: strength characteristics and workability bnost medium in hydraulic fluids. In the absence or at a content below the lower limit of any of the above components, the resulting reaction products, when introduced into the composition, do not provide the necessary cure speed and strength characteristics. The composition also does not withstand performance tests in the environment of hydraulic fluids. When using the components of the interaction products in a ratio above the stated limits, the resulting interaction products when introduced into the composition lead to delamination or premature polymerization of the latter, which makes the composition unsuitable for use.

Claims (1)

An anaerobic sealing composition based on a reaction mixture of (meth) acrylic monomer and oligourethane acrylate, including an initiator, inhibitor and functional additives, characterized in that it contains a mixture of the product of the interaction of hydroxyl-containing polybutadiene rubber SKD-GTPA, aromatic and / or aliphatic diisoci (meth) acrylate and water in their molar ratio, respectively (1-5) :( 2-6): 2: (0.001-0.1) and the product of the interaction of hydroxyl-containing (meth) acrylate, in s and 2,4-tolylene diisocyanate at molar ratio of respectively 2: (0.001-0.1): 1, with the following component ratio of the composition, in parts by weight .:
(meth) acrylic monomer 20.0-55.0 a mixture of 93-80 wt.% the product of the interaction of hydroxyl-containing polybutadiene rubber SKD-GTR, aromatic and / or aliphatic diisocyanate hydroxyl-containing (meth) acrylate and water and 7-20 wt.%. product interaction hydroxyl-containing (meth) acrylate, water and toluene diisocyanate 80.0-45.0 initiator 2.0-5.1 inhibitor 0.05-0.1 functional additives 4.0-20.0