Epoxy glue composition for bonding rubber sealing ring of wind generating set

Abstract

An epoxy glue composition for bonding a rubber sealing ring of a wind generating set comprises the following components in parts by weight: 80-100 parts of epoxy resin, 20-40 parts of polysulfide polyurea modified epoxy resin, 30-60 parts of a liquid nitrile rubber toughening agent with the nitrile group content of 10-20%, 10-50 parts of fatty amine, 0.1-5 parts of a curing accelerator, 0.1-1 part of a heat stabilizer, 0.1-4 parts of a coupling agent and 0.1-100 parts of filler, wherein the polysulfide polyurea modified epoxy resin is prepared by reacting liquid polysulfide rubber, epoxy resin and diisocyanate. The cured epoxy glue composition has the comprehensive properties of high strength, high toughness, high and low temperature resistance, oil resistance and the like, is used for bonding rubber sealing ring products, and is particularly suitable for bonding and repairing large sealing rings.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and in particular relates to an epoxy adhesive composition used for bonding a sealing ring of a wind turbine generator set. Background Art

[0002] At present, large-diameter rubber seals are required for bearing seals of wind turbines and other equipment. Due to the size limitation of the vulcanizing machine, large-diameter rubber seals need to be bonded with adhesives after vulcanization to prepare a complete rubber seal product; when the bearing seal is replaced, it is generally necessary to adopt an on-site rubber bonding process. However, rubber seals are in various harsh environments, such as high and low temperatures, extrusion and stretching conditions, as well as high temperatures and immersion in lubricating oils, which put forward stringent requirements on the performance of rubber adhesives. In addition to requiring adhesives to bond rubber with high strength, they must also meet the requirements of high toughness, high and low temperature resistance, and oil resistance. Adhesive technology is often used in existing rubber products. For example, rubber composite materials need to bond various skeleton materials to the rubber matrix as one, and vulcanized rubber is bonded to the metal substrate to play a damping and vibration reduction function. Invention patent application CN101693822A discloses an elastic epoxy adhesive and a bonding method thereof to achieve composite bonding between rubbers with complex structures of multiple cavities, wherein the epoxy adhesive composition, by weight, includes 10-50 parts of epoxy resin, 10-150 parts of liquid amino-terminated polybutadiene rubber, 0-50 parts of liquid amino-terminated polynitrile rubber, 1-5 parts of polyethylene polyamine, 1-100 parts of butanone and other solvents. In addition, there are many studies on epoxy adhesive toughening technology, such as invention patent application CN107142054A provides an impact-resistant epoxy adhesive composition, which is added with a composite toughening agent formed by at least a liquid rubber toughening agent with a core-shell structure, epoxy resin-modified nitrile rubber, ketoxime-terminated reactive polyurethane elastic prepolymer and epoxy resin-modified polysulfide rubber toughening agent, and the obtained epoxy adhesive composition has good impact resistance under both normal temperature and low temperature conditions. Summary of the invention

[0003] The present invention aims to provide an epoxy adhesive composition for bonding rubber sealing rings of wind turbine generator sets, which has comprehensive properties such as high bonding strength, high strength and high toughness, high and low temperature resistance and oil resistance after curing.

[0004] To solve the above technical problems, the present invention provides a technical solution: an epoxy adhesive composition for bonding rubber sealing rings of wind turbine generator sets, comprising the following components in parts by weight: 80 to 100 parts of epoxy resin, 20 to 40 parts of polysulfide polyurea modified epoxy resin, 30 to 60 parts of liquid nitrile rubber toughening agent with a nitrile content of 10-20%, 10 to 50 parts of fatty amine, 0.1 to 5 parts of curing accelerator, 0.1 to 1 part of heat stabilizer, 0.1 to 4 parts of coupling agent and 0.1 to 100 parts of filler.

[0005] The epoxy resin is a mixture of one or more of bisphenol A epoxy resin, bisphenol F epoxy resin and novolac epoxy resin.

[0006] The liquid nitrile rubber toughening agent with a nitrile content of 10-20% is 30-60 parts, preferably amino-terminated nitrile rubber (nitrile content of 10-20%), which has the characteristics of low-temperature toughening to reduce the stress of epoxy glue and improve the bonding and peeling force of the epoxy glue with the interface after curing.

[0007] The fatty amine is a mixture of one or more of 1,3-cyclohexanedimethylamine, isophoronediamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylmethane, methylcyclohexanediamine and polyamide.

[0008] The curing accelerator is a tertiary amine, preferably 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) accelerator.

[0009] The antioxidant is one or more of the following: antioxidant 168, antioxidant 1010, antioxidant DLTP, and hindered amine 770.

[0010] The coupling agent is selected according to needs, and KH560, KH550 and KH570 silane coupling agents can be selected.

[0011] The filler can be selected according to the needs, and can be one or a mixture of more than one of silicon micropowder, aluminum oxide, silicon dioxide, iron red and talcum powder.

[0012] The polysulfide polyurea modified epoxy resin is a product obtained by reacting 10 to 40 parts of liquid polysulfide rubber, 10 to 40 parts of epoxy resin and 0.5 to 4 parts of diisocyanate by weight; wherein the diisocyanate is preferably isophorone diisocyanate (IPDI) and toluene diisocyanate (TDI), and the number average molecular weight of the liquid polysulfide rubber is 800 to 1200.

[0013] The preparation method of the polythiopolyurea modified epoxy resin comprises the following steps: weighing 10 to 40 parts of liquid polythio rubber and 0.5 to 4 parts of diisocyanate in a container according to a proportion, reacting at 60 to 80° C. for 6 to 12 hours under nitrogen protection to prepare a mercapto-terminated polythiopolyurea prepolymer, then adding 10 to 40 parts of epoxy resin, and reacting for another 6 to 12 hours to obtain the polythiopolyurea modified epoxy resin.

[0014] The method of using the material of the present invention is as follows: before applying epoxy glue, a surface oxidation treatment agent is applied to the surface of the rubber to be bonded. The surface oxidation treatment agent can be nitric acid or a strong organic oxidant to form polar carbonyl groups, hydroxyl groups, etc. on the rubber surface, thereby strengthening the interaction with the epoxy glue to increase the bonding force and the oil resistance of the bonding interface.

[0015] The reaction formula of polythiourea modified epoxy resin is as follows:

[0016]

[0017] Compared with the prior art, the principles and beneficial effects of the present invention are as follows:

[0018] The present invention uses a liquid nitrile rubber with a nitrile content of 10-20% and a polysulfide polyurea modified epoxy resin in a certain proportion to jointly toughen a modified epoxy adhesive composition. Principle of the invention: (1) The epoxy adhesive toughened with a nitrile rubber with a low nitrile content has excellent low temperature resistance, but due to the low polar nitrile content, it has insufficient oil resistance. (2) The excellent oil resistance and toughening epoxy effect of low molecular weight polysulfide rubber are used to make up for the insufficient oil resistance of the nitrile rubber with a low nitrile content, but the low molecular weight polysulfide rubber has good compatibility with the epoxy resin, resulting in a decrease in the high temperature glass transition temperature of the toughened epoxy adhesive composition, affecting the high temperature resistance. (3) By introducing a polyurea structure into the liquid polysulfide rubber, the high temperature resistance of the toughened epoxy adhesive composition is improved by utilizing the hydrogen bonding effect of the polyurea, and the polar polyurea is also beneficial to improving the resistance to non-polar lubricating oils. Beneficial effects of the present invention: An epoxy adhesive composition is used for bonding rubber sealing ring products of large wind turbine generator sets. After curing, the epoxy adhesive composition has comprehensive properties such as high bonding strength, high strength and toughness, high and low temperature resistance and oil resistance. The epoxy adhesive composition of the present invention can also be used for bonding rubber sealing rings of bearings of other equipment, and is particularly suitable for bonding and repairing large sealing rings. DETAILED DESCRIPTION

[0019] Example 1

[0020] The invention discloses an epoxy adhesive composition for bonding a rubber sealing ring of a wind turbine generator set, comprising the following components in parts by weight: 100 parts of epoxy resin, 21 parts of polythiourea modified epoxy resin, 50 parts of amino-terminated nitrile rubber (nitrile content 18%), 28 parts of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4 parts of polyamide, 0.5 parts of DMP-30 accelerator, 0.5 parts of heat stabilizer, 1 part of KH560 coupling agent and 5 parts of silicon dioxide.

[0021] The epoxy resin is bisphenol A epoxy resin, and the antioxidant is a mixture of antioxidant 168, antioxidant 1010 and hindered amine 770 in a weight ratio of 2:1:1.

[0022] The polythiourea modified epoxy resin is prepared by reacting 10 parts of liquid polythio rubber, 10 parts of epoxy resin and 1 part of isophorone diisocyanate by weight. The preparation method comprises the following steps: weighing liquid polythio rubber and diisocyanate in a container according to a certain proportion, reacting them at 80°C for 6 hours under nitrogen protection, then adding epoxy resin and reacting them for 12 hours to obtain the polythiourea modified epoxy resin.

[0023] When the epoxy adhesive composition is bonded to nitrile rubber, the rubber surface is first treated with a chlorine-containing surface treatment agent and then cleaned with alcohol.

[0024] Example 2

[0025] The invention discloses an epoxy adhesive composition for bonding a rubber sealing ring of a wind turbine generator set, comprising the following components in parts by weight: 100 parts of epoxy resin, 20.8 parts of polythiourea modified epoxy resin, 50 parts of amino-terminated nitrile rubber (nitrile content 18%), 18 parts of 1,3-cyclohexanedimethylamine, 8 parts of polyamide, 0.5 parts of DMP-30 accelerator, 0.5 parts of heat stabilizer, 1 part of KH560 coupling agent and 5 parts of silicon dioxide.

[0026] The polysulfide-polyurea modified epoxy resin is prepared by reacting 10 parts of liquid polysulfide rubber, 10 parts of epoxy resin and 0.8 parts of toluene diisocyanate by weight, and the preparation method is the same as that of Example 1.

[0027] The main differences between Example 2 and Example 1 are that the curing agent is changed from 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane to 1,3-cyclohexyldimethylamine, and the isophorone diisocyanate in the polythiopolyurea-modified epoxy resin is changed to toluene diisocyanate.

[0028] Comparative Example 1

[0029] An epoxy adhesive composition comprises the following components in parts by weight: 100 parts of epoxy resin, 71 parts of amino-terminated nitrile rubber (nitrile content 18%), 28 parts of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4 parts of polyamide, 0.5 parts of DMP-30 accelerator, 0.5 parts of heat stabilizer, 1 part of KH560 coupling agent and 5 parts of silicon dioxide.

[0030] Note: In Comparative Example 1, compared with the epoxy adhesive composition of Example 1, 21 parts of polysulfide polyurea modified epoxy resin are replaced with 21 parts of amino-terminated nitrile rubber, so that the total amount of toughening agent in Comparative Example 1 is also maintained at 71 parts.

[0031] Comparative Example 2

[0032] The epoxy adhesive composition of Example 2 was used, and the nitrile rubber bonding surface was not treated, and only cleaned with alcohol. The test results of the epoxy adhesive compositions prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2, the material bulk properties after curing, and the rubber bonding strength are shown in the following table:

[0033]

[0034] The test results show that: (1) The material strength and elongation at break of Examples 1, 2 and the comparative example are all over 20MPa and 20% respectively, indicating that the epoxy adhesive composition modified by liquid nitrile rubber and polysulfide polyurea continues to maintain high strength and high toughness. (2) Compared with Comparative Example 1, Example 1: The high temperature loss peak temperature of the material is increased from 90°C to 104°C, and the retention strength of the rubber-rubber bonding tensile properties after oil immersion at 100°C×72h is significantly improved. (3) Compared with Comparative Example 2, Example 2 adopts the oxidation treatment of the rubber surface, and the T peel strength and bonding tensile strength are significantly improved, and the failure morphology of the rubber bonding test is transformed from interface failure to rubber cohesive failure.

[0035] The present invention adopts the technology of jointly modifying epoxy adhesive with liquid nitrile rubber having low nitrile group content and polysulfide polyurea, and improves high temperature resistance and oil resistance while maintaining high strength, high toughness and low temperature resistance of the epoxy adhesive composition, and has a significant effect of firmly bonding rubber sealing ring products.

Claims

1. An epoxy adhesive composition for bonding rubber sealing rings of wind turbine generator sets, comprising the following components in parts by weight: 80-100 parts of epoxy resin, 10-50 parts of fatty amine, 0.1-5 parts of curing accelerator, 0.1-1 parts of thermal stabilizer, 0.1-4 parts of coupling agent and 0.1-100 parts of filler, characterized in that There are also 20-40 parts of polythiourea modified epoxy resin and 30-60 parts of liquid nitrile rubber toughening agent with 10-20% nitrile group content; the polythiourea modified epoxy resin is a product formed by the reaction of 10-40 parts of liquid polythio rubber, 10-40 parts of epoxy resin and 0.5-4 parts of diisocyanate by weight.

Images