A long-lasting friction-reducing elevator wire rope grease composition, preparation method and application thereof

Abstract

The invention provides a long-acting friction-increasing elevator wire rope grease composition, a preparation method and application thereof, comprising the following raw materials in mass fraction: 45-70% of high-viscosity oil, 15-25% of wax ester thickener, 20-30% of terminal hydroxyl polybutadiene, 3-5% of diphenylmethane diisocyanate, 2-5% of cross-linking agent ethylene-acrylic acid copolymer, 1-5% of polyol chain extender, and 0.1-5.5% of functional additives. The viscosity of the high-viscosity oil at 100°C is 15-40 mm 2 / s, wax ester thickeners include one or more of palm wax, rice bran wax, sugarcane wax and polyester wax; functional additives include rust inhibitors, oiliness agents and antioxidants. The product of the present invention forms a solidified film containing polyurethane material between the steel wire rope and the elevator traction wheel groove, and the friction coefficient is maintained above 0.2 at 25-55°C, effectively reducing the wear of the steel wire rope and the wheel groove, and maintaining a long-term and stable friction-increasing effect.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating greases, and in particular relates to a long-acting friction-reducing elevator wire rope lubricating grease composition, a preparation method and application thereof. Background Art

[0002] Wire rope grease uses hydrocarbon grease, which is filled between the steel wires and the rope strands during the process of stranding and closing the wire rope by oil immersion or oil pouring to play a role in lubrication and rust prevention. In addition to lubrication and rust prevention, in order to provide traction in special working conditions such as traction elevators, mine friction hoists, and large cranes, a considerable static friction force needs to be maintained between the wire rope and the wheel groove to ensure the safe operation of the equipment. This requires the wire rope grease to play a role in increasing friction between the wire rope and the wheel groove. The friction coefficient at 25°C needs to reach more than 0.25 to ensure a sufficiently large static friction force.

[0003] The rapid increase in high-rise buildings has led to a rapid increase in the demand for high-speed elevator wire ropes. The increase in the height and speed of elevator operation has put forward new requirements for the safe operation of wire ropes. At present, the formula of elevator wire rope grease mostly uses high-viscosity mineral oils such as extracted oil, residue oil, and cyclohexane oil as the base oil, which has poor viscosity-temperature stability and oxidation stability; the friction enhancers are all modified phenolic resins, rosin resins and other resin compounds. Resin compounds have many benzene rings and high rigidity. The increase in the amount of addition will lead to an increase in the brittleness of the grease film. The repeated bending of the elevator wire rope will cause the oil film to break easily and discontinuously, resulting in an increase in the friction coefficient, but at the same time, the wear resistance will deteriorate. In addition, after adding a large amount of resin compounds, the low-temperature flexibility will deteriorate.

[0004] The traction wheel of a high-speed elevator has a high rotation speed, and the centrifugal force it generates easily causes the grease in the wire rope to be thrown out. The premature overflow of grease will cause insufficient lubrication between the wire rope and the wheel groove, resulting in a significant reduction in the friction coefficient, which in turn affects the traction force and the safe operation of the elevator. Therefore, adhesion is a key performance indicator of high-speed elevator wire rope grease. Insufficient grease adhesion leads to centrifugal throwing out, which affects the lifting force of the traction wheel and the sustainability of grease lubrication, affecting the life of the wire rope and the safe operation of the elevator. Summary of the invention

[0005] The object of the present invention is to provide a long-lasting friction-reducing elevator wire rope grease composition, a preparation method and application thereof. The wire rope grease composition of the present invention has a stronger affinity for metal surfaces and has excellent adhesion properties to elevator wire ropes.

[0006] The present invention provides a long-acting friction-reducing elevator wire rope grease composition, comprising the following raw materials in mass fractions:

[0007]

[0008] The viscosity of the high viscosity oil at 100°C is 15-40 mm 2 / s,

[0009] The wax ester thickener includes one or more of palm wax, rice bran wax, sugarcane wax and polyester wax;

[0010] The functional additives include rust inhibitors, oiliness agents and antioxidants.

[0011] Preferably, the high viscosity oil includes one or more of trimellitate, castor oil and alkyl diphenyl ether.

[0012] Preferably, the hydroxyl value of the terminal hydroxy butadiene is 0.47 to 0.8 mmol / g.

[0013] Preferably, the ethylene-acrylic acid copolymer includes one or more of ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer and ethylene-methyl methacrylate copolymer.

[0014] Preferably, the polyol chain extender includes one or more of polyethylene glycol, polypropylene glycol, butanediol, trimethylolpropane and triethanolamine.

[0015] Preferably, the long-acting friction-reducing elevator wire rope grease composition comprises the following functional additives in mass fraction:

[0016]

[0017] The present invention provides a method for preparing the long-acting friction-reducing elevator wire rope grease composition as described above, comprising the following steps:

[0018] A) mixing wax ester thickener and high viscosity oil, heating and dissolving and dispersing;

[0019] B) after the wax ester thickener is completely dissolved, the hydroxy-terminated polybutadiene is added and evenly dispersed, and then diphenylmethane diisocyanate is gradually added to carry out a prepolymerization reaction;

[0020] C) after the prepolymerization reaction is completed, the temperature is raised and a polyol chain extender is added to carry out a chain extension reaction;

[0021] D) after the chain extension reaction is completed, heating and adding ethylene-acrylic acid copolymer to carry out crosslinking reaction;

[0022] E) After the cross-linking reaction is completed, the temperature is raised to 140-160° C. for refining for 10-20 minutes, and after the refining is completed, a functional additive is added, and the mixture is stirred evenly to obtain a long-lasting friction-increasing elevator wire rope grease composition.

[0023] Preferably, the prepolymerization temperature is 80-100°C, and the prepolymerization time is 2-4 hours;

[0024] The temperature of the chain extension reaction is 90 to 110° C., and the time of the chain extension reaction is 0.5 to 2 hours;

[0025] The temperature of the cross-linking reaction is 120-140° C., and the time of the cross-linking reaction is 1-3 hours.

[0026] Preferably, after refining, the temperature is lowered to 80-100° C., a functional additive is added, and the mixture is stirred for 0.5-2 hours to obtain a long-lasting friction-reducing elevator wire rope grease composition.

[0027] The present invention provides application of the long-acting friction-reducing elevator steel wire rope grease composition as described above in a traction elevator steel wire rope.

[0028] The invention provides a long-acting friction-increasing elevator wire rope grease composition, comprising the following raw materials in mass fraction: 45-70% of high-viscosity oil, 15-25% of wax ester thickener, 20-30% of terminal hydroxyl polybutadiene, 3-5% of diphenylmethane diisocyanate, 2-5% of cross-linking agent ethylene-acrylic acid copolymer, 1-5% of polyol chain extender, and 0.1-5.5 of functional additives. The viscosity of the high-viscosity oil at 100°C is 15-40 mm 2 / s, the wax ester thickener includes one or more of palm wax, rice bran wax, sugarcane wax and polyester wax; the functional additive includes rust inhibitor, oiliness agent and antioxidant. The present invention uses palm wax, rice bran wax, polyester wax and other highly polar wax ester thickeners to thicken high viscosity ester oil or ether oil, thereby improving the affinity and adhesion to the metal surface, and the adhesion rate is 100% under the conditions of 65°C and 380r / min; in this oil-soap system, the polyurethane network structure is synthesized in situ, terminal hydroxyl polybutadiene and diphenylmethane diisocyanate are used for prepolymerization, polyols are used as chain extenders, and ethylene-acrylic acid copolymers are used as crosslinking agents to form a uniformly dispersed and stable polyurethane network structure. The product can form a cured film containing polyurethane material between the wire rope and the elevator traction wheel groove, and the friction coefficient can be maintained above 0.2 at 25-55°C, effectively reducing the wear of the wire rope and the wheel groove, and maintaining a long-term and stable friction-increasing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0030] Figure 1 This is the alternating load condition of the SRV variable load experiment in the embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention provides a long-acting friction-reducing elevator wire rope grease composition, comprising the following raw materials in mass fractions:

[0032]

[0033] The viscosity of the high viscosity oil at 100°C is 15-40 mm 2 / s,

[0034] The wax ester thickener includes one or more of palm wax, rice bran wax, sugarcane wax and polyester wax;

[0035] The functional additives include rust inhibitors, oiliness agents and antioxidants.

[0036] The present invention adopts a wax ester thickener with strong polarity to thicken high-viscosity ester oil / ether oil, which has better affinity and adhesion to metal surfaces than lubricating oil using hydrocarbon grease, and the adhesion rate is 100% under the conditions of 65°C and 380r / min.

[0037] Furthermore, the present invention uses terminal hydroxyl polybutadiene (HTPB), diphenylmethane diisocyanate (MDI) and ethylene-acrylic acid copolymer in the oil-soap system (high viscosity oil-wax ester thickener) to synthesize polyurethane elastomer in situ, and forms a network structure in the lubricating grease through a polyol cross-linking agent, so that the polyurethane material can be evenly dispersed in the lubricating grease, solving the oil solubility problem of the added polyurethane material, and the lubricating grease forms a solidified film containing the polyurethane material between the wheel groove and the steel wire rope to increase the friction coefficient, reduce the wear of the wheel groove and the steel wire rope, play the role of a tackifier and a friction enhancer, and solve the shortcomings of resin friction enhancers that the friction coefficient decreases with increasing temperature and the low temperature performance is poor;

[0038] Finally, the present invention adds high-performance additives such as rust inhibitors, oiliness agents, antioxidants, etc., and compounding obtains the long-acting friction-increasing elevator wire rope grease composition of the present invention.

[0039] In the present invention, the viscosity of the high viscosity oil at 100°C is preferably 15 to 40 mm 2 / s, the high-viscosity oil is preferably an ester oil and / or an ether oil, preferably including one or more of trimellitic acid esters, castor oil and alkyl diphenyl ether; the mass fraction of the high-viscosity oil is preferably 45-70%, more preferably 50-65%, such as 45%, 50%, 55%, 60%, 65%, 70%, preferably a range value with any of the above values ​​as the upper or lower limit.

[0040] In the present invention, the wax ester thickener preferably includes one or more of palm wax, rice bran wax, sugarcane wax and polyester wax, and the mass fraction of the wax ester thickener is preferably 15-25%, more preferably 18-22%, such as 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, preferably a range value with any of the above values ​​as the upper or lower limit.

[0041] In the present invention, the hydroxyl value of the hydroxyl-terminated polybutadiene is preferably 0.47-0.8 mmol / g, preferably including one or more of type I hydroxyl-terminated butadiene, type II hydroxyl-terminated butadiene, type III hydroxyl-terminated butadiene and type IV hydroxyl-terminated butadiene; the hydroxyl value of type I hydroxyl-terminated butadiene is 0.47-0.53 mmol / g; the hydroxyl value of type II hydroxyl-terminated butadiene is 0.54-0.64 mmol / g, the hydroxyl value of type III hydroxyl-terminated butadiene is 0.65-0.7 mmol / g, and the hydroxyl value of type IV hydroxyl-terminated butadiene is 0.71-0.8 mmol / g. The mass fraction of the hydroxyl-terminated polybutadiene is preferably 20-30%, more preferably 22-28%, such as 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, preferably a range value with any of the above values ​​as the upper or lower limit.

[0042] In the present invention, the purity of the diphenylmethane diisocyanate is preferably 98%, and the mass fraction of the diphenylmethane diisocyanate is preferably 3-5%, such as 3%, 4% or 5%, preferably a range value with any of the above values ​​as the upper or lower limit.

[0043] In the present invention, the ethylene-acrylic acid copolymer as a cross-linking agent preferably includes one or more of ethylene-acrylic acid copolymer (EAA), ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-butyl acrylate copolymer (EBA) and ethylene-methyl methacrylate copolymer (EMMA), and the mass fraction of the ethylene-acrylic acid copolymer is preferably 2-5%, more preferably 3-4%, such as 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, preferably a range value with any of the above values ​​as the upper or lower limit.

[0044] In the present invention, the polyol chain extender preferably includes one or more of polyethylene glycol, polypropylene glycol, butanediol, trimethylolpropane and triethanolamine; the mass fraction of the polyol chain extender is preferably 1-5%, more preferably 2-4%, such as 1%, 2%, 3%, 4%, 5%, preferably a range value with any of the above values ​​as the upper or lower limit.

[0045] In the present invention, the functional additives preferably include rust inhibitors, oiliness agents and antioxidants, and the rust inhibitors preferably include one or more of Span 85, sorbitan trioleate, barium petroleum sulfonate, zinc cyclohexaneate and lanolin magnesium soap; the mass fraction of the rust inhibitor is preferably 1-3%, more preferably 2-3%, such as 1%, 1.5%, 2%, 2.5%, 3%, preferably a range value with any of the above values ​​as the upper or lower limit.

[0046] In the present invention, the oiliness agent preferably includes one or more of boric acid esters, octadecylamine, sulphurized cottonseed oil, organic molybdenum salts and monoolein; the mass fraction of the oiliness agent is preferably 0.5-2%, more preferably 1-1.5%, such as 0.5%, 1%, 1.5%, 2%, preferably a range value with any of the above values ​​as the upper or lower limit.

[0047] In the present invention, the antioxidant preferably includes one or more of di-tert-butyl-p-cresol, diphenylamine, thiopropionate and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and the mass fraction of the antioxidant is preferably 0.1-0.5%, more preferably 0.2-0.4%, such as 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, preferably a range value with any of the above values ​​as the upper or lower limit.

[0048] The present invention also provides a method for preparing the above-mentioned long-acting friction-reducing elevator wire rope grease composition, comprising the following steps:

[0049] A) mixing wax ester thickener and high viscosity oil, heating and dissolving and dispersing;

[0050] B) after the wax ester thickener is completely dissolved, the hydroxy-terminated polybutadiene is added and evenly dispersed, and then diphenylmethane diisocyanate is gradually added to carry out a prepolymerization reaction;

[0051] C) after the prepolymerization reaction is completed, the temperature is raised and a polyol chain extender is added to carry out a chain extension reaction;

[0052] D) after the chain extension reaction is completed, heating and adding ethylene-acrylic acid copolymer to carry out crosslinking reaction;

[0053] E) After the cross-linking reaction is completed, the temperature is raised to 140-160° C. for refining for 10-20 minutes, and after the refining is completed, a functional additive is added, and the mixture is stirred evenly to obtain a long-lasting friction-increasing elevator wire rope grease composition.

[0054] In the present invention, the types and amounts of the wax ester thickener, high viscosity oil, terminal hydroxyl polybutadiene, diphenylmethane diisocyanate, polyol chain extender, ethylene-acrylic acid copolymer and functional additives are consistent with the types and amounts of the wax ester thickener, high viscosity oil, terminal hydroxyl polybutadiene, diphenylmethane diisocyanate, polyol chain extender, ethylene-acrylic acid copolymer and functional additives described above, and the present invention will not be repeated here.

[0055] The invention firstly mixes the wax ester thickener and the high-viscosity oil, and heats the mixture to dissolve and disperse the mixture, so that the wax ester thickener is completely dissolved.

[0056] In the present invention, the dissolution and dispersion temperature is preferably 80-100°C, more preferably 90-95°C, such as 80°C, 85°C, 90°C, 95°C, 100°C, preferably a range value with any of the above values ​​as the upper or lower limit.

[0057] After the wax ester thickener is completely dissolved, the present invention adds the terminal hydroxyl polybutadiene therein to disperse it evenly, and then gradually adds diphenylmethane diisocyanate to carry out a prepolymerization reaction.

[0058] In the present invention, the temperature of the prepolymerization reaction is preferably 80-100°C, more preferably 90-95°C, such as 80°C, 85°C, 90°C, 95°C, 100°C, preferably a range value with any of the above numerical values ​​as the upper or lower limit; the time of the prepolymerization reaction is preferably 2-4 hours, more preferably 2-3 hours.

[0059] After the prepolymerization reaction is completed, the temperature is raised and a polyol chain extender is added to carry out a chain extension reaction.

[0060] In the present invention, the temperature of the chain extension reaction is preferably 90-110°C, more preferably 95-100°C, such as 90°C, 95°C, 100°C, 105°C, 110°C, preferably a range value with any of the above values ​​as the upper or lower limit; the time of the chain extension reaction is preferably 0.5-2 hours, more preferably 1-1.5 hours.

[0061] After the chain extension reaction is completed, the temperature is raised and ethylene-acrylic acid copolymer is added to carry out a cross-linking reaction.

[0062] In the present invention, the temperature of the cross-linking reaction is preferably 120-140°C, more preferably 130-135°C, such as 120°C, 125°C, 130°C, 135°C, 140°C, preferably a range value with any of the above values ​​as the upper or lower limit; the time of the cross-linking reaction is preferably 1-3 hours, more preferably 1.5-2 hours.

[0063] After the cross-linking reaction is completed, the present invention heats up the cross-linked system and performs refining. After the refining is completed, the temperature is lowered to 80-90° C., a functional additive is added, and the mixture is stirred for 1-2 hours to obtain a long-acting friction-increasing elevator wire rope grease composition.

[0064] In the present invention, the refining process dissociates the wax ester thickener network structure by heating, and entangles with the formed polyurethane network structure, so that the polyurethane network is evenly and stably distributed in the grease, ensuring the stability of the friction coefficient at different contact positions after the solidified film is formed, while improving the structural strength of the grease at high temperature and improving the friction-increasing effect at high temperature. The uniform distribution of the polyurethane network at low temperature can block the co-crystallization effect of the wax ester thickener and improve the low-temperature brittleness. The refining temperature is preferably 140 to 160°C, more preferably 145 to 155°C, such as 140°C, 145°C, 150°C, 155°C, 160°C, preferably a range value with any of the above values ​​as the upper or lower limit; the refining time is preferably 10 to 20 minutes, more preferably 15 to 20 minutes.

[0065] The present invention also provides an application of the long-lasting friction-reducing elevator wire rope grease composition described above in a traction elevator wire rope. The grease composition of the present invention is used for the wire rope, and can maintain the long-lasting temperature friction-reducing effect and viscosity-increasing effect during the high-speed operation of the wire rope.

[0066] The invention provides a long-acting friction-increasing elevator wire rope grease composition, comprising the following raw materials in mass fraction: 45-70% of high-viscosity oil, 15-25% of wax ester thickener, 20-30% of terminal hydroxyl polybutadiene, 3-5% of diphenylmethane diisocyanate, 2-5% of cross-linking agent ethylene-acrylic acid copolymer, 1-5% of polyol chain extender, and 0.1-5.5% of functional additives. The viscosity of the high-viscosity oil at 100°C is 15-40 mm 2 / s, the wax ester thickener includes one or more of palm wax, rice bran wax, sugarcane wax and polyester wax; the functional additive includes rust inhibitor, oiliness agent and antioxidant. The present invention uses highly polar wax ester thickeners such as palm wax, rice bran wax and polyester wax to thicken high-viscosity ester oil or ether oil to improve the affinity and adhesion to the metal surface, and the adhesion rate is 100% under the conditions of 65°C and 380r / min; in this oil-soap system, a highly polar polyurethane network structure is synthesized in situ, terminal hydroxyl polybutadiene and diphenylmethane diisocyanate are used for prepolymerization, polyols are used as chain extenders, and ethylene-acrylic acid copolymers are used as crosslinking agents to form a uniformly dispersed and stable polyurethane network structure. On the one hand, it acts as a thickener to increase the viscosity of grease and improve its viscosity-temperature performance; on the other hand, the grease can form a solidified film containing polyurethane material between the wire rope and the wheel groove, forming a friction pad at the molecular level. The friction coefficient can be maintained above 0.2 at 25-55°C, effectively reducing the wear of the wire rope and the wheel groove, maintaining a long-term and stable friction-increasing effect, and solving the shortcomings of the currently used resin friction-increasing agents such as modified phenolic resin, which are brittle, poor low-temperature performance, poor high-temperature friction-increasing effect, and insufficient wear resistance.

[0067] In order to further illustrate the present invention, a long-acting friction-reducing elevator wire rope grease composition, a preparation method and an application thereof provided by the present invention are described in detail below in combination with embodiments, but it should not be construed as limiting the scope of protection of the present invention.

[0068] Example 1

[0069] 450g of alkyl diphenyl ether base oil was added to the kettle, and 200g of polyester wax was added after the temperature was raised to 90°C to dissolve and disperse. After complete dissolution and dispersion, 250g of terminal hydroxyl polybutadiene IV type was added and stirred and dispersed. After uniform dispersion, 50g of diphenylmethane diisocyanate was slowly added for prepolymerization for 3 hours, and then the temperature was raised to 100°C and 50g of trimethylolpropane was added for chain extension reaction for 1 hour. After the reaction was completed, the temperature was raised to 130°C and 30g of ethylene-acrylic acid copolymer was added for cross-linking reaction for 1.5 hours. The temperature was raised to 150°C and refined for 15 minutes, then the temperature was lowered to 90°C, 10g of Span 80, 10g of zinc cyclohexaneate rust inhibitor, 5g of octadecylamine, 5g of monooleyl glycerol oiliness agent and 2g of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester antioxidant were added, stirred and dispersed for 1 hour, and then the kettle was removed.

[0070] Example 2

[0071] Add 500g of castor oil base oil to the kettle, heat it to 90℃, add 150g of palm wax to dissolve and disperse it, add 270g of terminal hydroxyl polybutadiene III type and stir and disperse it after dissolution, slowly add 40g of diphenylmethane diisocyanate after uniform dispersion for prepolymerization reaction for 3 hours, then heat it to 100℃ and add 40g of polyethylene glycol for chain extension reaction for 1 hour, after the reaction is completed, heat it to 130℃ and add 30g of ethylene-ethyl acrylate copolymer for cross-linking reaction for 1.5 hours, heat it to 150℃ and refine it for 15min, then cool it to 90℃, add 15g of Span 80, 5g of sorbitan trioleate rust inhibitor, add 10g of borate oiliness agent and 3g of di-tert-butyl-p-cresol antioxidant, stir and disperse for 1 hour and then remove from the kettle.

[0072] Example 3

[0073] Add 450g of trimellitic acid ester base oil into the kettle, heat it to 90℃, add 200g of rice bran wax to dissolve and disperse it, add 280g of terminal hydroxyl polybutadiene II type and stir and disperse it after dissolution, slowly add 30g of diphenylmethane diisocyanate and carry out prepolymerization reaction for 3 hours after uniform dispersion, then heat it to 100℃ and add 40g of trimethylolpropane to carry out chain extension reaction for 1 hour, after the reaction is completed, heat it to 130℃ and add 30g of ethylene-methyl acrylate copolymer to carry out cross-linking reaction for 1.5 hours, heat it to 150℃ and refine it for 15min, then cool it to 90℃, add 20g of petroleum barium sulfonate rust inhibitor, add 20g of organic molybdenum salt oiliness agent and 5g of diphenylamine antioxidant, stir and disperse for 1 hour, and then remove from the kettle.

[0074] Comparative Example 1

[0075] Add 450g of alkyl diphenyl ether base oil to the kettle, heat it to 90℃, add 200g of polyester wax to dissolve and disperse it, add 140g of polyether polyol after complete dissolution and dispersion, stir and disperse it, slowly add 140g of diphenylmethane diisocyanate after uniform dispersion for prepolymerization reaction for 3 hours, then heat it to 100℃ and add 70g of polypropylene glycol for chain extension reaction for 1 hour, after the reaction is completed, heat it to 130℃ and add 30g of ethylene-butyl acrylate copolymer for cross-linking reaction for 1.5 hours, heat it to 150℃ and refine it for 15min, then cool it to 90℃ and add 20g of Span 80, add 10g of monoolein glycerol oiliness agent and 3g of di-tert-butyl-p-cresol antioxidant, stir and disperse for 1 hour and then remove from the kettle.

[0076] The thickening and viscosity-increasing effects of polyether polyurethane are poor, and the thin consistency leads to average adhesion and abrasion-increasing effects.

[0077] Comparative Example 2

[0078] 450g of trimellitic acid base oil was added to the kettle, and 200g of polyester wax was added after the temperature was raised to 90°C to dissolve and disperse. After complete dissolution and dispersion, 140g of polyester polyol was added and stirred to disperse. After uniform dispersion, 122g of diphenylmethane diisocyanate was slowly added to carry out prepolymerization for 3 hours, and then the temperature was raised to 100°C and 88g of butanediol was added to carry out chain extension reaction for 1 hour. As the reaction proceeded, white insoluble particles appeared, which could not be dissolved even at 220-230°C. The maximum refining temperature of the reactor for industrial production of grease and the tolerable temperature of the base oil were both below 230°C. The polyester polyurethane had poor oil solubility after in-situ synthesis and could not play a viscosity-increasing and friction-increasing effect.

[0079] Comparative Example 3

[0080] 450g of aromatic mineral oil was added to the kettle, and 200g of polyester wax was added after the temperature was raised to 90°C to dissolve and disperse. After complete dissolution and dispersion, 250g of terminal hydroxyl polybutadiene IV type was added and stirred and dispersed. After uniform dispersion, 50g of diphenylmethane diisocyanate was slowly added for prepolymerization for 3 hours, and then the temperature was raised to 100°C and 50g of trimethylolpropane was added for chain extension reaction for 1 hour. After the reaction was completed, the temperature was raised to 130°C and 30g of ethylene-acrylic acid copolymer was added for cross-linking reaction for 1.5 hours. The temperature was raised to 150°C and refined for 15 minutes, then the temperature was lowered to 90°C, 10g of Span 80, 10g of zinc cyclohexaneate rust inhibitor, 5g of octadecylamine, 5g of monooleyl glycerol oiliness agent and 2g of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester antioxidant were added, stirred and dispersed for 1 hour, and then the kettle was removed.

[0081] Aromatic oil has poor compatibility with wax esters and polyurethane. After the system is cooled, the grease has a rough appearance, a low dropping point, and poor adhesion and friction-increasing effects.

[0082] Comparative Example 4

[0083] 450g of aromatic mineral oil was added to the kettle, and 200g of microcrystalline wax was added after the temperature was raised to 90°C to dissolve and disperse. After complete dissolution and dispersion, 250g of terminal hydroxyl polybutadiene IV was added and stirred and dispersed. After uniform dispersion, 50g of diphenylmethane diisocyanate was slowly added for prepolymerization for 3 hours, and then the temperature was raised to 100°C and 50g of trimethylolpropane was added for chain extension reaction for 1 hour. After the reaction was completed, the temperature was raised to 130°C and 30g of ethylene-acrylic acid copolymer was added for cross-linking reaction for 1.5 hours. The temperature was raised to 150°C. During the refining process, white insoluble particles were precipitated. Microcrystalline wax is a long-chain hydrocarbon non-polar compound and has poor compatibility with highly polar polyurethane elastomers. They cannot entangle with each other to form a network structure. The molecular weight of the polyurethanes continued to increase under high temperature, resulting in poor oil solubility and precipitation, which cannot play a viscosity-increasing and friction-increasing effect.

[0084] Comparative Example 5

[0085] Take the commercially available ordinary elevator wire rope grease as comparative example 1;

[0086] Comparative Example 6

[0087] Take the common friction-increasing grease available on the market as comparative example 2.

[0088] The performance of the grease compositions obtained in the examples and comparative examples was tested, and the results are shown in Table 1.

[0089] Table 1 Typical performance data of products in Examples and Comparative Examples

[0090]

[0091] The "SRV25℃ long-term wear friction coefficient" and "SRV55℃ long-term wear friction coefficient" in Table 1 are both obtained by testing using the OptimolSRV micro-motion friction and wear tester. The specific test methods are as follows:

[0092] The ball-disc friction test block of the SRV reciprocating friction tester was used to simulate the micro-motion wear of the steel wires under contact conditions. The ball-disc was made of the same material, with a Young's modulus of 2100 MPa. An alternating load test with a load increase of 50N to 400N was used. A three-cycle alternating load test was performed with "holding 30s at 50N load, holding 15min at 100N load, and then increasing the load from 100N to 400N after 2min" as one cycle. Figure 1 As shown. According to the Hertz stress theory calculation formula, the Hertz contact stress between the ball-disk friction pair ranges from 1.7 to 3.4 GPa, with an amplitude of 1 mm and a frequency of 10 Hz. A temperature control module is used to conduct reciprocating friction tests at two temperatures of 25°C and 55°C. The friction coefficient is recorded during the test and the average friction coefficient of different formulations is compared.

[0093] The “25°C SRV long wear volume” in Table 1 was measured by using a MicroXAM-800 three-dimensional profiler to measure the wear scar volume.

[0094] It can be seen from the data in Table 1 that the in-situ synthesized polybutadiene polyurethane elastomer is weaker in polarity than polyester polyurethane (Comparative Example 2) and polyether polyurethane (Comparative Example 1), and has better compatibility with ester / ether base oils and wax ester thickeners, and has better oil solubility and dispersibility. In addition, the polymer has better flexibility, viscoelasticity, water resistance and stability. The polybutadiene polyurethane elastomer can be physically cross-linked with polar wax ester thickeners, entangled with each other to form a network structure, and the ethylene-acrylic acid copolymer as a cross-linking agent strengthens the entangled network structure and improves the compatibility of the polyurethane elastomer and the wax ester thickener. The use of ester / ether base oils instead of cycloparaffin oils and aromatic oils (Comparative Examples 3 and 4) helps to disperse this network structure in the base oil.

[0095] The contact part of the friction pair between the steel wires of the steel wire rope coated with steel wire grease is in boundary lubrication under load working conditions. The polyurethane elastomer-wax ester thickener improves the oil film strength as a skeleton structure. Compared with traditional hydrocarbon grease, it has stronger polarity and stronger affinity for metal surfaces and stronger adhesion. The butadiene polyurethane network structure has stronger elasticity. After being loaded, the network structure changes from curled to elongated, providing a friction-increasing effect. After the load disappears, it returns to its original state. This reciprocating process can provide long-term friction-increasing and a stable friction coefficient. Compared with polyester or polyether polyurethane, it is more prone to creep after being subjected to alternating loads. After the load disappears, the elastomer structure cannot return to its original state. Long-term work will produce long-chain polymer shearing into short-chain polymers, affecting the friction-increasing effect. Compared with traditional friction-increasing agents such as modified phenolic resin and rosin resin, it has stronger flexibility, and the formed cured film is not easy to break due to sliding. The polyurethane network structure can improve the viscosity-temperature property, improve the viscosity of the steel wire rope grease at high temperatures, and prevent the friction coefficient from being significantly reduced at high temperatures.

[0096] The grease composition of the present invention has excellent friction-increasing and adhesion properties, the SRV long-wear friction coefficient at 25°C and 55°C is above 0.2, and the long-wear wear volume is significantly lower than that of commercially available products; the adhesion rate is 100% under the conditions of 65°C and 380r / min, the high-temperature adhesion performance is excellent, and it does not crack at a low temperature of -35°C, thus solving the problem of poor low-temperature properties of currently commercially available friction-increasing greases.

[0097] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A long-lasting friction-reducing elevator wire rope grease composition, comprising the following raw materials by mass fraction: The viscosity of the high viscosity oil at 100°C is 15-40 mm 2 / s, The wax ester thickener includes one or more of palm wax, rice bran wax, sugarcane wax and polyester wax; The functional additives include rust inhibitors, oiliness agents and antioxidants.

2. The long-acting friction-reducing elevator wire rope grease composition according to claim 1, characterized in that: The high viscosity oil includes one or more of trimellitate, castor oil and alkyl diphenyl ether.

3. The long-acting friction-reducing elevator wire rope grease composition according to claim 1, characterized in that: The hydroxyl value of the terminal hydroxy butadiene is 0.47 to 0.8 mmol / g.

4. The long-acting friction-reducing elevator wire rope grease composition according to claim 1, characterized in that: The ethylene-acrylic acid copolymer includes one or more of ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer and ethylene-methyl methacrylate copolymer.

5. The long-acting friction-reducing elevator wire rope grease composition according to claim 1, characterized in that: The polyol chain extender includes one or more of polyethylene glycol, polypropylene glycol, butanediol, trimethylolpropane and triethanolamine.

6. The long-acting friction-reducing elevator wire rope grease composition according to claim 1, characterized in that: The long-acting friction-increasing elevator wire rope grease composition comprises the following functional additives in mass fraction: Rust inhibitor 1~3% Oiliness agent 0.5~2% Antioxidant 0.1~0.5%.

7. A method for preparing the long-acting friction-reducing elevator wire rope grease composition according to claim 1, comprising the following steps: A) mixing wax ester thickener and high viscosity oil, heating and dissolving and dispersing; B) after the wax ester thickener is completely dissolved, the hydroxy-terminated polybutadiene is added and evenly dispersed, and then diphenylmethane diisocyanate is gradually added to carry out a prepolymerization reaction; C) after the prepolymerization reaction is completed, the temperature is raised and a polyol chain extender is added to carry out a chain extension reaction; D) after the chain extension reaction is completed, heating and adding ethylene-acrylic acid copolymer to carry out crosslinking reaction; E) After the cross-linking reaction is completed, the temperature is raised to 140-160° C. for refining for 10-20 minutes, and after the refining is completed, a functional additive is added, and the mixture is stirred evenly to obtain a long-lasting friction-increasing elevator wire rope grease composition.

8. The preparation method according to claim 7, characterized in that: The prepolymerization reaction temperature is 80-100°C, and the prepolymerization reaction time is 2-4 hours; The temperature of the chain extension reaction is 90 to 110° C., and the time of the chain extension reaction is 0.5 to 2 hours; The temperature of the cross-linking reaction is 120-140° C., and the time of the cross-linking reaction is 1-3 hours.

9. The preparation method according to claim 7, characterized in that: After the refining is completed, the temperature is lowered to 80-100° C., a functional additive is added, and the mixture is stirred for 0.5-2 hours to obtain a long-acting friction-increasing elevator wire rope grease composition.

10. Use of the long-lasting friction-reducing elevator wire rope grease composition according to claim 1 in traction elevator wire ropes.

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