RU2374290C1 - Anaerobic sealing composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to an anaerobic sealing composition based on (meth)acrylic monomers, used as sealer for components made from aluminium alloys, steel and cast iron, for example when making car engines. This composition consists of the following components, pts. wt: 100 - reactive mixture 28 to 96 pts. wt of one or more methacrylic monomers and 72 to 4 pts. wt urethane acrylate, 4.0 to 11.5 - initiator, 0.025 to 0.1 - inhibitor and 6.7 to 87.5 - functional additives. The urethane acrylate contained in the composition is a product of reacting oligodiol, 2,4-toluene diisocyanate, hydroxyl-containing (meth)acrylate and water in molar ratio of (1-8):2:(2-9):(0.001-0.1) respectively, and the functional additives are in form of filler, thickeners, plasticisers, dyes and other substances.

EFFECT: anaerobic composition has high rate of hardening, good adhesion and cohesion properties, which improves airtightness of flange coupling.

17 ex, 1 tbl

Description

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

The developed anaerobic composition is used instead of traditional solid sealing gaskets for sealing parts made of alloys of aluminum, steel and cast iron. It is applied to the surface of the part, then the mating surface is superimposed on it, and curing occurs in the formed gap to obtain a polymer layer that is sufficiently elastic with the required adhesive strength and acts as a gasket formed in place. This technology is used in the manufacture of automobile engines, but can be applied in other industries.

Domestic automakers put forward the following requirements for anaerobic sealing compositions:

- when curing on products from aluminum alloys at 20-25 ° C in 1 hour, at least 50% strength should be achieved, which in 24 hours should be within 6-16 MPa (separation);

- the composition should ensure the tightness of the flange connection, withstanding a pressure of 0.6 MPa 45 minutes after application.

The anaerobic composition, which is used as a gasket, in the conditions of conveyor production should quickly cure and gain the necessary strength in a short period. High curing speed is especially relevant for surfaces made of aluminum and its alloys, as they are inactive for anaerobic curing materials. The anaerobic sealing composition should, when cured, form a gasket having a tensile strength of 6-16 MPa. Less strength does not provide tightness, and greater complicates the dismantling of the device if necessary.

Thus, the creation of an anaerobic sealing composition having such optimal desired properties is a complex and urgent task.

Known anaerobic liquid gasket (US patent No. 4629755, C08F 220/12, publ. 16.12.1986), consisting of the following components, wt.%:

alkyl methacrylate, where C ₆ -C ₁₃ alkyl alkoxyalkyl methacrylate 20-95 hydroxyalkyl methacrylate aromatic methacrylate, 80-5 cycloaliphatic and heterocyclic rings

For 100 parts by weight a mixture of these monomers, the composition contains, by weight:

- organic peroxide 0.01-10 - anaerobic curing accelerator, for example a mixture in a mass ratio 1: 1 orthobenzosulfimide and amine compounds selected from the group containing heterocyclic secondary or tertiary amine and aromatic tertiary amine 0.2-10 - filler, for example hydrated silicon dioxide 10-50 - stabilizer, for example a mixture in bulk 1: 1 ratio of phosphinic acid and ethylenediaminotetramethylene phosphinic acid 0.002-1.0

The disadvantage of this composition is the slow curing, which does not provide the required technological and operational characteristics of the anaerobic strip.

Also known is an anaerobic curing composition for sealing an automobile engine according to US Pat. No. 4,985,523, C08F 26/02, publ. 01/15/1991. The claimed composition is used on flange surfaces, including those made of dissimilar materials (aluminum-iron), characterized by different coefficients of thermal expansion. The composition includes, by weight:

monofunctional (meth) acrylic monomer 15-60 (phenoxyethyl acrylate, dicyclopentenyloxy- ethyl methacrylate or a mixture thereof) molecular oligourethane (meth) acrylate 40-75 weighing at least 10,000 molecular oligourethane (meth) acrylate 0-40 weighing 500-5000

For 100 parts by weight the specified monomer mixture, the composition according to examples contains, parts by weight:

stabilizer - disodium salt ethylenediaminotetraacetic acid 0.02 and oxalic acid 0.01 initiator - hydroperoxide cumyl 1,0 o-benzosulfimide 1,0 N-ethyl methatoluidine 0.2

The oligourethane (meth) acrylates used are synthesized by the interaction of three components:

- diol (polyoxypropylated diphenylolpropane with terminal hydroxyethylene groups, or hydroxyethylated diphenylolpropane, or polybutanedioladipinate);

- diisocyanate (trimethylhexamethylene diisocyanate);

- hydroxyethyl methacrylate.

The cured compositions at 25 ° C for 24 hours have a shear strength on steel samples of 2.1-2.4 MPa. When these samples are heated at 150 ° C for 30 days, the indicated strengths increase to 3.7–4.1 MPa. This indicates that the composition at 25 ° C in 24 hours is cured by 57.5%, that is, incompletely. It can be concluded that the composition has a low polymerization rate at 25 ° C and therefore will not provide the required tightness 45 minutes after application under a pressure of 0.6 MPa.

The prototype of the invention is an anaerobic curable sealing composition according to patent EP1131363, C08F 20/18, publ. May 28, 2003

The composition includes, wt.%:

(meth) acrylate resins 65-75 methacrylate monomers 15-19 hardeners and stabilizers 2-4 thickeners and dyes 6-8 phosphomethacrylate promoter adhesion 0.5-5

As (meth) acrylate resins, the composition contains urethane acrylates of polyalkylene, polyoxyalkylene, ester oligomers and others.

Methacrylate monomers include mono- or polyfunctional methacrylic esters such as triethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, trimethylol propanetri (meth) acrylate, 2-hydroxyethyl (meth) acrylate, methyl (meth) acrylate and others.

Hardeners used are peroxides, hydroperoxides, peracids, peracids esters and N, N-dimethyl-p-toluidine, acetylphenylhydrazine, saccharin, maleic acid or mixtures thereof.

Hydroquinone, benzoquinone, ethylenediaminetetraacetic acid, beta-diketones, etc. are used as stabilizers.

The examples given in the patent specification EP 1131363 show that the prototype compositions cured at room temperature for 24-72 hours have shear strengths of 2.5-4.88 MPa on aluminum plates. The composition proposed according to the prototype is effective for a long time to form gaskets on aluminum substrates. A significant disadvantage of the prototype is the low speed set of strength characteristics. Hardening proceeds slowly, as evidenced by the data given after 24-72 hours.

In the patent EP 1131363 described anaerobic sealing composition Loctite 5205, which contains, by weight:

(meth) acrylic polyurethane 72.68 methacrylic monomers 18.03 naphthoquinone and ethylenediaminotetraacetic acid 0.54 saccharin 0.3 1-aceto-2-phenylhydrazine 0.45 dyes 1,1 Cumila hydroperoxide 1.83 silica 5.06

With the addition of 2% by weight of the phosphorus-containing adhesion promoter Ebecryl 168 (a mixture of hydroxypropylmethacrylate phosphates), the shear strength on aluminum plates is 4.88 N / mm ² when incorporated into the composition of the Loctite 5205 sealant. We reproduced the composition of the prototype, containing 98 wt.% Loctite 5205 and 2 wt.% Ebecryl 168, showed an increased setting time (30 minutes), a low tensile strength at break after 1 hour of curing at room temperature (not more than 4 MPa), and depressurization of the flange joint after 45 minutes of curing occurred at a pressure of 0.3 MPa.

The technical result of the invention is to increase the curing rate of the anaerobic sealing composition and improve the tightness of flange joints using it.

To achieve the technical result, an anaerobic sealing composition based on a reactive mixture of one or more methacrylic monomers and urethane acrylate, including initiator, inhibitor and functional additives, contains urethane acrylate as the reaction product of oligodiol, 2,4-toluene diisocyanate, hydroxyl-containing (meth) acrylate and water their molar ratio, respectively (1-8): 2: (2-9) :( 0.001-0.1) with the following content of the components of the composition, parts by weight:

a mixture of 28.0-96.0 parts by weight methacrylic monomer one hundred and 72.0-4.0 parts by weight specified product interactions of oligodiol, 2,4-toluylene di- hydroxyl-containing isocyanate (meth) acrylate and water initiator 4.0-11.5 inhibitor 0.025-0.1 functional additives 6.7-87.5

As methacrylic monomers, alkylene glycol di- and monomethacrylates and mixtures thereof are used, for example triethylene glycol dimethacrylate (TGM-3), methoxyethylene glycol methacrylate (MDEM), hydroxyethyl methacrylate (MEG), hydroxypropyl methacrylate (MPGM) and octyl methacrylate (MPGM) and octyl methacrylate (MPGM) and octyl methacrylate (MPGM) and octyl methacrylate (MPGM) and octyl methacrylate (MPGM) and octyl methacrylate (MPGM) and octyl methacrylate (MPGM) and octyl methacrylate (MPGM) and

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-oxopiperidin-1-oxyl (nitroxin-1), naphthoquinone, hydroquinone, trilon-B, etc. are used in the composition of the inhibitory system.

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

As oligodiols, hydroxyl-containing polyesters can be used - polymerization products of ethylene oxide (propylene) and glycols, as well as hydroxyl-containing rubbers.

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

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

Example No. 1

The method of obtaining the product of the interaction of hydroxyl-containing polyester, 2,4-toluene diisocyanate, hydroxyethyl methacrylate and water with a molar ratio of 2: 2: 3: 0.003 (product A)

100 parts by weight are charged to the reactor. (0.047 mol) of a hydroxyl-containing polyester of the Laprol 2102 brand and at a temperature not exceeding 35 ° C, 12.18 parts by weight are metered with stirring. (0.07 mol) 2,4-toluene diisocyanate (2,4-TDI). Stirring is continued at 55-60 ° C for 2.5-3 hours. until the content of isocyanate groups reaches ~ 1.76%. Then, over a period of 3-4 hours, 6.11 parts by weight are dosed. (0.047 mol) of hydroxyethyl methacrylate (MEG) containing 0.00117 parts by weight (0.000065 mol) of water and 0.059 parts by weight the catalyst is tin dibutylcaprylate (DOC). At the end of dosage, the reaction mass is maintained at 55-60 ° C until the isocyanate groups disappear (according to the IR spectrum).

The finished product is a slightly yellowish transparent viscous mass.

Example No. 2

The method of obtaining the product of the interaction of hydroxyl-containing polyester, 2,4-toluene diisocyanate, hydroxypropylmethacrylate and water with a molar ratio of 8: 2: 9: 0.001 (product B)

68.9 parts by weight are charged to the reactor. (0.12 mol) of hydroxyl-containing polyester brand Laprol 502 and with stirring, 20.9 wt.h. (0.135 mol) 2,4-TDI, maintaining a temperature of 35-40 ° C. Then the temperature is raised to 50-60 ° C and the reaction mass is stirred for 10-15 hours. Upon reaching the content of isocyanate groups of ~ 1.36%, 4.32 parts by weight are metered into the reaction mass. (0.03 mol) of hydroxypropyl methacrylate (PGM) containing 0,000324 parts by weight (0.000018 mol) of water and 0.047 parts by weight DOC. The reaction mass is stirred at 50-60 ° C until the isocyanate groups disappear.

The finished product is an amorphous colorless mass.

Example No. 3

The method of obtaining the product of the interaction of hydroxyl-containing oligomeric rubber, 2,4-toluene diisocyanate, hydroxypropylmethacrylate and water with a molar ratio of 1: 2: 2: 0.05 (product B).

78 parts by weight are charged to the reactor. (0.034 mol) of oligomeric hydroxyl-containing rubber of the SKD-GTRA brand and at a temperature of 45-50 ° C, 11.83 parts by weight are metered. (0.068 mol) 2.4-TDI. Stirring is continued at 55-60 ° C for 2-3 hours until the content of isocyanate groups reaches ~ 3.18%. Then, 9.79 parts by weight are metered into the reaction mass. (0.068 mol) of PGM containing 0.0306 parts by weight (0.0017 mol) of water and 0.05 parts by weight DOC. The reaction mass is stirred at 55-60 ° C until the isocyanate groups disappear.

The finished product is a viscous mass of brown.

Example No. 4

The method of obtaining the product of the interaction of hydroxyl-containing oligomeric rubber, 2.4-toluene diisocyanate, hydroxypropylmethacrylate and water at a molar ratio of 3: 2: 4: 0.1 (product D)

102 parts by weight are charged into the reactor. (0.0465 mol) of hydroxyl-containing oligomeric rubber of the brand Crasol-LBH (manufacturer - Unipetrol, Czech Republic) and 10.79 parts by weight are metered with stirring. (0.062 mol) 2,4-TDI, maintaining a temperature of 30-35 ° C. Stirring is continued at 55-60 ° C for 4-5 hours. Upon reaching the content of isocyanate groups of ~ 1.15%, 4.46 parts by weight are metered into the reaction mass. (0.031 mol) of PGM containing 0.027 parts by weight of (0.0015 mol) of water and 0.059 parts by weight DOC. The reaction mass is stirred at 55-60 ° C until the isocyanate groups disappear.

The finished product is a viscous transparent mass of yellowish color.

The following are examples of the preparation and testing of an anaerobic sealing composition.

Example No. 5

An anaerobic sealing composition is prepared by mixing in a glass reactor 8.7 wt.h. triethylene glycol dimethacrylate (TGM-3), 19.3 parts by weight methoxydiethylene glycol methacrylate (MDEM), 72.0 parts by weight product A, 1.44 parts by weight o-benzosulfimide (BSI), 0.56 wt.h. acetylphenylhydrazine (AFH), 2.44 parts by weight cumyl hydroperoxide (GPC), 0.019 parts by weight disodium salt of ethylenediamine-N, N, N ′, N′-tetra-acetic acid (Trilon B), 0.003 wt.h. oxalic acid, 0.033 parts by weight 2,2,6,6-tetramethyl-4-oxopiperidin-1-oxyl (nitroxyl-1), 1.0 parts by weight acrylic acid, 0.1 parts by weight dye organic fat-soluble dark red "Zh" and 5.6 wt.h. aerosil. The tests are carried out as follows

Setting time and tensile strength at separation is determined according to GOST 14760-69. An anaerobic spacer is applied to the surface of aluminum samples (fungi), the samples are combined, curing is carried out at 20-25 ° C. The set time is taken to be the time after which when the hand rotates the upper "fungus" relative to the fixed lower "fungus" the sample does not shift. The tensile strength at separation is determined after 1 and 24 hours on a testing machine according to GOST 28840-90 at a moving gripping speed of 20 mm / min.

Determination of the sealing ability is carried out on a deadweight tester type MP-600. Anaerobic gasket is applied to the contacting surfaces of the flange connection, tighten the flange connection with fixing bolts with a force of 50 ± 1 N · m. The flanges are maintained at 20-25 ° C for 45 minutes, after which they are placed on the MP-600 pressure gauge. The pressure is raised at a speed of 0.1 MPa per minute to 0.6 MPa and maintained at 0.6 MPa for 5 minutes. If the hydraulic fluid does not flow out of the flange connection, then the anaerobic gasket is considered to have passed the test.

The composition and test results are shown in the table.

Example No. 6

An anaerobic sealing composition is prepared by mixing in a glass reactor 61.3 wt.h. TGM-3, 27.7 parts by weight octyl methacrylate (OMAC), 7.0 parts by weight PGM, 4.0 parts by weight Product B, 2.13 parts by weight BSI, 0.77 parts by weight AFG, 3.68 parts by weight tert-butyl hydroperoxide (GPTB), 0.031 parts by weight Trilon B, 0.002 parts by weight 4,4'-bis (dimethylamino) triphenylmethane oxalate (malachite green), 0.025 parts by weight nitroxyl-1, 38.9 parts by weight dioctyl phthalate (DOP), 27.2 parts by weight a copolymer of butyl methacrylate and methyl methacrylate (copolymer MB-20), 0.1 wt.h. dye organic fat-soluble green anthraquinone, 9.7 wt.h. powdered fluoroplast-4 (F-4), 2.68 wt.h. isooctylphenol polyoxyethylene ether (OP-7) and 8.92 parts by weight aerosil.

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

Example No. 7

An anaerobic sealing composition is prepared by mixing in a glass reactor 33.3 wt.h. ethylene glycol dimethacrylate (DMEG), 11.1 parts by weight MEG, 40.0 parts by weight OMAC, 15.6 parts by weight product B, 1.95 parts by weight BSI, 0.5 parts by weight AFG, 1.55 parts by weight HPA, 0.007 parts by weight Trilon B, 0.008 parts by weight hydroquinone, 0.01 wt.h. nitroxyl-1, 8.35 parts by weight low molecular weight polystyrene (PSN), 0.1 wt.h. dye organic fat-soluble dark red W, 6.24 wt.h. DOP and 11.18 parts by weight aerosil.

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

Example No. 8

An anaerobic sealing composition is prepared by mixing in a glass reactor 31.8 wt.h. tetraethylene glycol dimethacrylate (TGM-4), 68.2 parts by weight product G, 1.43 parts by weight BSI, 5.61 parts by weight telomer of butyl acrylate and triethylamine (TBT), 0.64 parts by weight AFG, 3.82 parts by weight HPA, 0.024 parts by weight Trilon B, 0.008 parts by weight ionol, 0.04 parts by weight nitroxyl-1, 7.95 parts by weight triallyl isocyanurate (TAIC), 14.63 parts by weight polypropylene glycol adipate dibutyl ether (PDEA-4), 12.56 parts by weight copolymer MB-20, 0.08 wt.h. dye organic fat-soluble bright blue anthraquinone and 12.4 wt.h. aerosil.

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

Example No. 9

An anaerobic sealing composition is prepared by mixing in a glass reactor 26.7 wt.h. polyethylene glycol dimethacrylate (TGM-13), 16.2 parts by weight MEG, 18.1 parts by weight α, ω-methacryl- (bis-triethylene glycol) phthalate (MGF-9), 39.0 parts by weight product B, 0.6 parts by weight dimethisaratholuidine (DMPT), 0.6 wt.h. dibenzosulfimide (DBSI), 0.45 parts by weight AFG, 2.27 parts by weight GPC, 0.03 parts by weight γ-bipyridyl, 0.05 parts by weight naphthoquinone, 0.02 parts by weight para-methoxyphenol (MOF), 7.55 parts by weight copolymer of vinyl chloride with vinyl acetate (copolymer BX-VA), 12.84 parts by weight polypropylene glycol adipate dibutyl ether (PPA-7), 0.03 parts by weight dye organic fat-soluble yellow W, 10.57 wt.h. powdered polyethylene (LDPE) and 15.1 wt.h. aerosil.

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

Examples No. 10-16 (for comparison)

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

From the data given in the table it can be seen that the setting time of the claimed composition is at room temperature 12-20 minutes, tensile strength at break-off after 1 hour is 6-9 MPa, after 24 hours 7-10 MPa. The prototype, these indicators, respectively, 30 min, 4 and 11 MPa (see examples No. 5-9 compared with No. 10). From these indicators it is seen that the cure rate of the claimed composition is higher than that of the prototype. As a result, the inventive composition ensures the tightness of the flange connection at a pressure of 0.6 MPA 45 minutes after application, and the composition of the prototype of this test does not stand up.

A distinctive feature of the claimed composition in comparison with the prototype is the use in the composition as a urethane acrylate of the product of the interaction of oligodiol, 2,4-toluene diisocyanate, hydroxyl-containing methacrylate and water, with their molar ratio, respectively (1-8): 2: (2-9) :( 0.001 -0.1) in an amount of 4-72 parts by weight per 100 parts by weight polymerization mixture.

Examples No. 11-12 show that when used in the composition of the composition of the specified product, the interaction in amounts outside the claimed leads to a decrease in the curing rate and an increase in setting time.

The examples in the table No. 13-17 prove that reducing the setting time and improving the tightness of the compounds is achieved by introducing into the composition of the product the product of the interaction of oligodiol, 2,4-toluene diisocyanate, hydroxyl-containing methacrylate and water (cf. examples 5 and 13, 6 and 14, 7 and 15, 8 and 16, 9 and 17). Compositions that do not contain the specified interaction product do not pass the leak test, cure more slowly (setting time increases, after 1 hour less than 50% of full strength is reached).

As a result of the interaction of oligodiol, 2,4-toluene diisocyanate, hydroxyl-containing (meth) acrylate and water in the ratio specified in the present invention, a mixture of polymerizable oligomers is formed, which, together with other ingredients of the proposed composition, provides the necessary speed of curing and formation of gaskets with high adhesive and cohesive properties. In the absence or at a content below the lower limit of any of the above components, the composition does not pass the leak test. When using components in a ratio above the stated limits, the resulting product of interaction when introduced into the composition leads to delamination or premature polymerization of the latter, which makes the composition unsuitable for use.

Claims (1)

An anaerobic sealing composition based on a reactive mixture of one or more methacrylic monomers and urethane acrylate, including an initiator, inhibitor and functional additives, characterized in that it contains the reaction product of oligodiol, 2,4-toluene diisocyanate, hydroxyl-containing (meth) acrylate and water when their molar ratio, respectively (1-8): 2: (2-9) :( 0.001-0.1) with the following content of the components of the composition, parts by weight:
a mixture of 28-96 parts by weight methacrylic monomer and 72-4 parts by weight specified interaction product oligodiol, 2,4-toluene diisocyanate, hydroxyl-containing (meth) acrylate and water one hundred initiator 4.0-11.5 inhibitor 0.025-0.1 functional additives 6.7-87.5