JP5832727B2 - Manufacturing method of elevator rope - Google Patents

Description

  The present invention relates to an elevator rope that is used in an elevator and suspends a car.

Conventionally, in an elevator apparatus, a sheave having a diameter of 40 times or more the rope diameter is used in order to prevent early wear and disconnection of the rope. Therefore, in order to reduce the diameter of the sheave, it is necessary to reduce the diameter of the rope. However, if the rope diameter is reduced without changing the number of ropes, the load resistance of the ropes is reduced, and the weight of luggage that can be loaded onto the car and passengers getting on and off the car are reduced. Moreover, the increase in the number of ropes complicates the configuration of the elevator apparatus. Further, when the diameter of the drive sheave is reduced, repeated bending fatigue of the rope increases, and the rope needs to be frequently replaced.
As means for solving these problems, a strand is formed by twisting a plurality of steel wires, a wire rope is formed by twisting a plurality of strands, and the outermost periphery of the wire rope is covered with a resin material. It has been proposed to use a rope (see, for example, Patent Document 1). An elevator using such a rope is driven by a frictional force between a sheave and a resin material constituting the outermost periphery of the rope. Therefore, it is desired to stabilize or improve the friction characteristics of the resin material. Then, in order to improve the friction characteristic of the rope for elevators, it has been proposed to use a rope covered with a polyurethane coating material not containing wax (for example, see Patent Document 2). On the other hand, in order to reduce the coefficient of friction between the sheave and the belt within a predetermined range, a flat belt coated with a polyether-based thermoplastic polyurethane elastomer added with isoparaffin wax having a low oil content has been proposed. (For example, see Patent Document 3). Furthermore, even in a situation where oil adheres to the contact surface between the sheave and the rope or belt, in order to obtain a rope and belt in which the friction coefficient is not significantly reduced and the resin coating is less worn by sliding, a resin base material is obtained. A rope and belt coated with a resin coating mixed with insoluble solid additive particles, particularly insoluble solid additive particles having a hardness greater than the hardness of the surface member of the sheave, have been proposed (see, for example, Patent Document 4). .

  In general, it is known that the friction coefficient of a resin material greatly depends on the sliding speed and temperature. Furthermore, it is also known that viscoelastic properties such as dynamic viscoelasticity of a resin material have a conversion property (Williams-Landel-Ferry equation (WLF equation)) between the speed and temperature dependency. Furthermore, in the case of rubber friction, the same conversion property holds for the sliding speed and temperature, which indicates that the viscoelastic properties of rubber are involved in the friction properties of the rubber (for example, , See Non-Patent Document 1).

JP 2001-262482 A JP-T-2004-538382 International Publication No. 2007/128622 JP 2009-234791 A

Grosch, K. A .: Proc. Roy. Soc., A274, 21 (1963)

  As can be seen from the above, even with a polyurethane coating material that does not contain wax described in Patent Document 2, the friction coefficient of the material itself changes depending on the sliding speed and temperature, so that the elevator cannot be braked stably. There was a problem. Furthermore, as described in Non-Patent Document 1, the friction coefficient of rubber has a maximum value with respect to the sliding speed. In order for the elevator to stop for a long time, it is necessary to maintain the stationary state of the car due to the frictional force between the rope and the sheave. Such a coating material to which isoparaffin wax having a low oil content is added has a problem that the friction coefficient at a minute sliding speed cannot be secured above a certain level, and the stop position of the car shifts with time. Moreover, in order to make an emergency stop or a sudden stop of the elevator in operation, it is necessary to brake the elevator by the frictional force between the rope and the sheave. However, the conventional covering materials as described in Patent Documents 1 to 4 However, there is a problem that the friction coefficient between the rope and the sheave is remarkably reduced as a result of strength reduction and melting caused by frictional heat.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an elevator rope having a stable coefficient of friction regardless of temperature and sliding speed.

The inventors examined the friction characteristics of various resin materials. FIG. 1 is an example of the results showing the frequency dependence of the loss modulus in materials with different friction coefficient sliding speed dependences. As can be seen from FIG. 1, the inventors have found that a material having a small friction coefficient dependency on a sliding speed has a small frequency dependency on a loss elastic modulus in a viscoelastic master curve. Based on this knowledge, the present inventors have studied the composition of the resin material, and as a result, in order to reduce the frequency dependence of the loss elastic modulus and the friction speed, the thermoplastic polyurethane elastomer A molded article of a resin coating layer forming composition in which a blocked isocyanate obtained by reacting a blocking agent with an isocyanate compound having two or more isocyanate groups in one molecule is provided as a resin coating layer of an elevator rope Has been found to be effective, and the present invention has been completed.
That is, the present invention relates to a rope main body, and a block isocyanate obtained by reacting a blocking agent with a thermoplastic polyurethane elastomer covering an outer periphery of the rope main body and an isocyanate compound having two or more isocyanate groups in one molecule. An elevator rope comprising a resin coating layer made of a molded product of a resin coating layer forming composition in which is mixed.

  According to the present invention, from a molded article of a resin coating layer forming composition obtained by mixing a thermoplastic polyurethane elastomer and a blocked isocyanate obtained by reacting a blocking agent with an isocyanate compound having two or more isocyanate groups in one molecule. Since the outer periphery of the rope body is covered with the resin coating layer, an elevator rope having a stable coefficient of friction can be obtained without depending on the temperature and the sliding speed.

It is an example of the result (viscoelastic master curve) which shows the frequency dependence of the loss elastic modulus in the material from which the sliding speed dependence of a friction coefficient differs. It is a conceptual diagram of the apparatus for measuring the friction coefficient in the micro slip velocity area used in the Example. It is a conceptual diagram of the apparatus for measuring the friction coefficient at the time of the emergency stop used in the Example.

Embodiments of the present invention will be described below.
Embodiment 1 FIG.
The elevator rope according to Embodiment 1 of the present invention is characterized in that the outer periphery of the rope body is coated with a molded body of a resin coating layer forming composition in which a thermoplastic polyurethane elastomer and a blocked isocyanate are mixed.

Examples of the thermoplastic polyurethane elastomer used in the present embodiment include ester-based thermoplastic polyurethane elastomer, ether-based thermoplastic polyurethane elastomer, ester-ether-based thermoplastic polyurethane elastomer, carbonate-based thermoplastic polyurethane elastomer, and the like. These may be used alone or in combination of two or more. Among these thermoplastic polyurethane elastomers, ether-based thermoplastic polyurethane elastomers are preferably used in order to prevent hydrolysis that occurs in the environment of use, and considering the flexibility and durability of elevator ropes, JIS A hardness (JIS K7215). It is more preferable to use a polyether-based thermoplastic polyurethane elastomer having a hardness of 85 to 95 in accordance with the type A durometer defined by the above.
Moreover, it is preferable to use the thermoplastic polyurethane elastomer processed into the pellet form or the flake form from the point of handleability, such as mixing with block isocyanate.

  The blocked isocyanate used in the present embodiment is obtained by reacting a blocking agent with an isocyanate compound having two or more isocyanate groups in one molecule. As the isocyanate compound having two or more isocyanate groups in one molecule, organic diisocyanate compounds such as aliphatic diisocyanate compounds, alicyclic diisocyanate compounds, aromatic diisocyanate compounds, and araliphatic diisocyanate compounds are used. Specific examples of the aliphatic diisocyanate compound include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, undecamethylene diisocyanate, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane. , Trimethylhexane-1,6-diisocyanate, 1,11-diisocyanatoundecane, 1,12-dodecane diisocyanate, lysine diisocyanate and the like. Specific examples of the alicyclic diisocyanate compound include isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-diisocyanatocyclobutane, 1,4-diisocyanatocyclohexane, 4,4′-di Isocyanatodicyclohexylmethane, 1,2-bis (isocyanatomethyl) cyclobutane, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 4,4'-cyclohexane diisocyanate, isopropylidenebis (4-cyclohexyl) isocyanate 1,3-bis (isocyanatomethyl) cyclobutane, bis (isocyanatomethyl) norbornane, 3 (4), 8 (9) -diisocyanatomethyltricyclo (5.2.2.12.6) decane, 1,3-diisocyanatocyclohexane, Examples include 1,3- or 1,4-diisocyanatomethylcyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate). Specific examples of the aromatic diisocyanate compound include tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, diphenylmethane-4,4′-diisocyanate, 3-methyldiphenylmethane-4,4′-diisocyanate, m- Or p-phenylene diisocyanate etc. are mentioned. Specific examples of the araliphatic diisocyanate compound include m- or p-xylylene diisocyanate, tetramethylxylylene diisocyanate, 4,4-bis (isocyanatomethyl) diphenylmethane, and the like. These may be used alone or in combination of two or more. Among these organic diisocyanate compounds, aromatic aliphatic diisocyanates are preferable from the viewpoints of availability, mechanical strength properties as rope coating materials, and durability, and tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate. Diphenylmethane-4,4′-diisocyanate is particularly preferred.

Known blocking agents include phenolic, alcoholic, active methylene, mercaptan, acid amide, acid imide, imidazole, urea, carbamic acid, oxime, amine, imine, pyrazole, etc. The blocking agent for isocyanate is used. Specific examples of the phenolic blocking agent include phenol, cresol, ethylphenol, butylphenol and the like. Specific examples of the alcohol blocking agent include methanol, ethanol, 2-ethylhexanol, ethylene glycol, benzyl alcohol and the like. Specific examples of the active methylene-based blocking agent include dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate and the like. Specific examples of the mercaptan block agent include butyl mercaptan, dodecyl mercaptan and the like. Specific examples of the acid amide blocking agent include acetanilide, acetic acid amide, ε-caprolactam, δ-valerolactam, γ-butyrolactam and the like. Specific examples of the acid imide blocking agent include succinimide and maleic imide. Specific examples of the imidazole blocking agent include imidazole and 2-methylimidazole. Specific examples of the urea blocking agent include urea, thiourea, and ethylene urea. Specific examples of the carbamic acid blocking agent include phenyl N-phenylcarbamate. Specific examples of the oxime blocking agent include formal oxime, acetoald oxime, methyl ethyl ketoxime, cyclohexanone oxime, acetoxime, diacetyl monooxime, benzophenone oxime, and the like. Specific examples of the amine blocking agent include diphenylamine, aniline, carbazole and the like. Specific examples of the imine blocking agent include ethyleneimine and polyethyleneimine. Specific examples of the pyrazole-based blocking agent include 3,5-dimethylpyrazole. These may be used alone or in combination of two or more. Among these blocking agents, oxime blocking agents are preferable, and methyl ethyl ketoxime is particularly preferable.
The blocked isocyanates obtained from the above raw materials may be used alone or in combination of two or more.

  The resin coating layer in the present embodiment is a molding machine such as an extrusion molding machine or an injection molding machine after mixing the above-described thermoplastic polyurethane elastomer and the above-described blocked isocyanate to form a resin coating layer-forming composition. It is obtained by covering the outer periphery of the rope body. In the present embodiment, the mixing ratio of the thermoplastic polyurethane elastomer and the blocked isocyanate varies depending on the type of the thermoplastic polyurethane elastomer and the blocked isocyanate to be used, but the obtained molded article has a JIS A hardness of 98 or less and a glass transition. What is necessary is just to adjust suitably in the range from which temperature becomes -20 degrees C or less. For example, when using a polyether-based thermoplastic polyurethane elastomer having a JIS A hardness of 95 and a blocked isocyanate obtained by blocking the isocyanate group of diphenylmethane-4,4′-diisocyanate with methyl ethyl ketoxime, 100 parts by mass of the thermoplastic polyurethane elastomer, It is preferable to mix the block isocyanate at a ratio of 3 parts by mass or more and 15 parts by mass or less. If the amount of blocked isocyanate is less than 3 parts by mass, crosslinking may be insufficient, and the effect of stabilizing the friction coefficient independent of temperature and sliding speed may not be sufficiently exerted. However, the improvement of the effect commensurate with the above is not recognized, rather it is economically disadvantageous, and other physical properties of the obtained crosslinked product may be deteriorated.

Embodiment 2. FIG.
In the elevator rope according to the second embodiment of the present invention, the outer periphery of the rope body has an aromatic diisocyanate, an average molecular weight of 450 or more and 4000 or less, a high molecular weight polyol of 2 functional groups, an average molecular weight of 60 or more and less than 450 diol, and an average molecular weight of 60. A thermoplastic polyurethane elastomer obtained by reacting a chain extender comprising a mixture of triols of less than 450 and a blocked isocyanate obtained by reacting a blocking agent with an isocyanate compound having two or more isocyanate groups in one molecule; It is characterized in that it is coated with a molded body of a resin coating layer forming composition in which is mixed.

  Specific examples of the aromatic diisocyanate used to obtain the thermoplastic polyurethane elastomer of Embodiment 2 include tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, diphenylmethane-4,4′-diisocyanate, Examples include 3-methyldiphenylmethane-4,4′-diisocyanate, m- or p-phenylene diisocyanate. These may be used alone or in combination of two or more. Among these, diphenylmethane-4,4'-diisocyanate is preferable from the viewpoints of availability, mechanical strength properties as a rope coating material, and durability.

  The high molecular weight polyol used to obtain the thermoplastic polyurethane elastomer of Embodiment 2 may be a polyol having an average molecular weight of 450 or more and 4000 or less and a functional group number of 2, for example, adipic acid, sebacin One or more acids selected from acids, dodecanedioic acid, isophthalic acid and azelaic acid and one or more glycols selected from ethylene glycol, diethylene glycol, propanediol, butanediol, pentanediol, hexanediol and neopentylglycol And polyester polyol, polycaprolactone polyol, polycarbonate polyol, polytetramethylene glycol, polypropylene glycol and the like obtained by reacting with each other. These may be used alone or in combination of two or more. Among these, the ether-based thermoplastic polyurethane elastomer is preferable as the thermoplastic polyurethane elastomer for the same reason as described in Embodiment 1, and therefore polytetramethylene glycol having an average molecular weight of 450 or more and 4000 or less is preferable.

The diol used as a chain extender for obtaining the thermoplastic polyurethane elastomer of the second embodiment may be a diol having an average molecular weight of 60 or more and 450 or less, such as ethanediol, butanediol, pentanediol, hexane. Examples include diol, diethylene glycol, dipropylene glycol, cyclohexane diol, and polytetramethylene glycol. Further, the triol used as the chain extender of the thermoplastic polyurethane elastomer of Embodiment 2 may be a triol having an average molecular weight of 60 or more and 450 or less, such as glycerin, trimethylolethane, trimethylolpropane, hexane. And triols.
The mixing ratio of the diol and the triol contained in the chain extender is 1 mol or more, more preferably 3 mol or more and 7 mol or less with respect to 1 mol of the triol. If the blending ratio of the diol is too small, the melt viscosity of the obtained thermoplastic polyurethane elastomer becomes too high, and the moldability and processability may be deteriorated.
The thermoplastic polyurethane elastomer of the second embodiment can be produced by a known production method as described in, for example, Japanese Patent No. 4076893.

  Moreover, as block isocyanate, the thing similar to illustrated in Embodiment 1 can be used, and these may be used independently and may be used in combination of 2 or more types. The mixing ratio of the thermoplastic polyurethane elastomer and the blocked isocyanate varies depending on the type of the thermoplastic polyurethane elastomer and the blocked isocyanate to be used, but, as in the first embodiment, the JIS A hardness of the obtained molded product is 98 or less and What is necessary is just to adjust suitably in the range from which glass transition temperature will be -20 degrees C or less. Moreover, the method similar to Embodiment 1 can be applied to the method for forming the resin coating layer.

Embodiment 3 FIG.
In the elevator rope according to Embodiment 3 of the present invention, the outer periphery of the rope body has an aromatic diisocyanate, an average molecular weight of 450 or more and 4000 or less, a high molecular weight polyol having a functional group number of 2.1 or more and less than 3, and an average molecular weight of 60 or more and less than 450. A resin coating layer in which a thermoplastic polyurethane elastomer obtained by reacting a chain extender composed of a diol and a blocked isocyanate obtained by reacting a blocking agent with an isocyanate compound having two or more isocyanate groups in one molecule It is characterized by being covered with a molded body of the forming composition.

  The high molecular weight polyol used to obtain the thermoplastic polyurethane elastomer of Embodiment 3 may be a polyol having an average molecular weight of 450 or more and 4000 or less and a functional group number of 2.1 or more and less than 3, A polyol similar to that exemplified in Form 2 can be used. Furthermore, two or more types of high molecular weight polyols having different numbers of functional groups are mixed to adjust the average number of functional groups to 2.1 or more and less than 3, or an excess polyol and isocyanate are reacted to make one molecule. A polyol prepolymer having the number of hydroxyl groups contained adjusted to 2.1 or more and less than 3 can also be used. Among these, polypropylene glycol, polytetramethylene glycol (number of functional groups: 2) having an average molecular weight of 450 or more and 4000 or less and a functional group number of 2.1 or more and less than 3 from the viewpoint of availability, mechanical strength properties as a rope coating material, and durability. ) And polypropylene glycol having a functional group number greater than 2 are preferred, and a polyol mixture adjusted to have an average functional group number of 2.1 or more and less than 3 is preferred.

  Further, the aromatic diisocyanate and the diol as the chain extender used for obtaining the thermoplastic polyurethane elastomer of the third embodiment can be the same as those exemplified in the second embodiment.

  As blocked isocyanate, the thing similar to what was illustrated in Embodiment 1 can be used, and they may be used independently and may be used in combination of 2 or more types. The mixing ratio of the thermoplastic polyurethane elastomer and the blocked isocyanate varies depending on the type of the thermoplastic polyurethane elastomer and the blocked isocyanate to be used, but, as in the first embodiment, the JIS A hardness of the obtained molded product is 98 or less and What is necessary is just to adjust suitably in the range from which glass transition temperature will be -20 degrees C or less. Moreover, the method similar to Embodiment 1 can be applied to the method for forming the resin coating layer.

  In addition, the resin coating layer forming composition described in the first to third embodiments may further be mixed with an inorganic filler in order to further stabilize the friction coefficient with respect to temperature and sliding speed. Examples of such inorganic fillers include spherical inorganic fillers such as calcium carbonate, silica, titanium oxide, carbon black, acetylene black, and barium sulfate, fibrous inorganic fillers such as carbon fiber and glass fiber, mica, and talc. And plate-like inorganic fillers such as bentonite. These may be used alone or in combination of two or more. Among these, it is preferable to use a fibrous inorganic filler and a plate-like inorganic filler in order to reduce the variation of the friction coefficient. The hardness of these inorganic fillers is not particularly limited. What is necessary is just to adjust the compounding quantity of these inorganic fillers suitably in the range from which the JISA hardness of the molded object obtained is 98 or less and glass transition temperature to -20 degrees C or less.

The reason why the JIS A hardness of the molded body is defined as 98 or less is that if it exceeds 98, the flexibility of the rope is impaired, and there is a tendency that the power consumption increases when this is applied to an elevator and driven. It was because it was understood by the study of the people. The JIS A hardness of the molded body is more preferably 85 or more and 95 or less.
The reason why the glass transition temperature of the molded body is specified to be −20 ° C. or lower is that the higher the glass transition temperature of the molded body, the smaller the dependency of the friction coefficient on the sliding speed, but the lower the glass transition temperature of the molded body. The higher the modulus, the higher the modulus of elasticity of the molded body, and when this is applied to an elevator rope as a resin coating layer, the flexibility of the rope decreases and the rope is repeatedly bent in an environment higher than the glass transition temperature of the molded body. This is because the inventors have studied that the stress applied to the resin coating layer tends to cause fatigue failure such as cracking of the resin coating layer. The glass transition temperature of the molded body is more preferably −25 ° C. or lower.

  In addition, since the rope for elevators according to Embodiments 1 to 3 is characterized by the outermost resin material covering the outer periphery of the rope body, the structure of the rope body is not particularly limited, Generally, a strand or a cord formed by twisting a plurality of steel wires is included as a load supporting member. The rope body in the present embodiment may be in the form of a belt including the above-described strands or cords. In addition, in order to improve the adhesion between the rope body and the resin coating layer, a metal such as Chemlock (registered trademark) 218 (manufactured by Road Far East) and an adhesive for polyurethane are preliminarily applied to the above strands or cords. It is preferable to keep it. In addition, the elevator rope according to the present embodiment is heated to about 100 ° C. to 120 ° C. after the outermost resin is coated, in order to promote the crosslinking of the thermoplastic polyurethane elastomer by the blocked isocyanate and to cure the adhesive. The

  According to the first to third embodiments, in a wide range of sliding speeds from a small sliding speed range necessary for maintaining the elevator car in a stationary state to a large sliding speed range when the operating elevator is emergency stopped or suddenly stopped. Thus, it is possible to obtain an elevator rope having a small variation in the friction coefficient.

Hereinafter, although an example and a comparative example explain the present invention still in detail, the present invention is not limited to these.
<Example 1>
Diphenylmethane-4,4′-diisocyanate (aromatic diisocyanate), polytetramethylene glycol (high molecular weight polyol) having an average molecular weight of 1000 g / mol, and butanediol (chain extender) are mixed with diphenylmethane-4,4′-diisocyanate. An ether-based thermoplastic polyurethane elastomer was obtained by mixing and polymerizing so that the sum of the hydroxyl equivalents of the high molecular weight polyol and the chain extender was 1 with respect to 1 equivalent of the isocyanate. The obtained ether-based thermoplastic polyurethane elastomer had a JIS A hardness of 85.
A mixture of 100 parts by mass of the JIS A hardness 85 ether thermoplastic polyurethane elastomer obtained above and 10 parts by mass of blocked isocyanate obtained by reacting diphenylmethane-4,4′-diisocyanate with methyl ethyl ketoxime. Was supplied to an extrusion molding machine and molded as a resin coating layer covering the outer periphery of the rope body. After the rope body was coated with the resin coating layer, it was heated at 110 ° C. for 2 hours in order to accelerate the crosslinking reaction of the thermoplastic polyurethane elastomer and cure the adhesive to obtain an elevator rope having a diameter of 12 mm. In addition, the obtained rope for elevators has a cross-sectional structure described in FIG. 1 of International Publication No. 2003/050348. Here, the rope body includes an inner layer rope having a plurality of core ropes in which a plurality of steel strands are twisted together and a plurality of inner layer strands in which a plurality of steel strands are twisted, and an inner layer rope It corresponds to a resin inner layer covering covering the outer periphery, and an outer layer rope provided on the outer peripheral portion of the inner layer covering, and having an outer layer rope with a plurality of steel strands twisted together, The resin coating layer corresponds to the outer layer covering. Before the rope body was coated with the resin coating layer, Chemlock (registered trademark) 218 (manufactured by Road Far East) was applied to the outer layer cord and dried.

<Example 2>
An elevator rope was obtained in the same manner as in Example 1 except that the JIS A hardness of the ether-based thermoplastic polyurethane elastomer described in Example 1 was changed from 85 to 95.

<Example 3>
Diphenylmethane-4,4′-diisocyanate (aromatic diisocyanate), polytetramethylene glycol (high molecular weight polyol) having an average molecular weight of 1000 g / mol, a mixture of butanediol and trimethylolpropane (chain extender, butanediol and trimethylol) The molar ratio of propane and propane is 5.9: 1) so that the sum of the hydroxyl equivalents of the high molecular weight polyol and the chain extender is 1.08 with respect to 1 equivalent of diphenylmethane-4,4′-diisocyanate. And polymerized to obtain an ether-based thermoplastic polyurethane elastomer. The obtained ether-based thermoplastic polyurethane elastomer had a JIS A hardness of 85.
An elevator rope was obtained in the same manner as in Example 1 except that this ether-based thermoplastic polyurethane elastomer was used instead of the ether-based thermoplastic polyurethane elastomer described in Example 1.

<Example 4>
Mixture of diphenylmethane-4,4′-diisocyanate (aromatic diisocyanate), polytetramethylene glycol having an average molecular weight of 1000 g / mol and polypropylene glycol having an average molecular weight of 1000 g / mol and an average functional group number of 2.4 (high molecular weight polyol mixture, poly A weight ratio of tetramethylene glycol to polypropylene glycol (1: 1) and butanediol (chain extender) of high molecular weight polyol mixture and chain extender to 1 equivalent of diphenylmethane-4,4'-diisocyanate. Mixing was performed so that the sum of hydroxyl equivalents was 1.08, and polymerization was performed to obtain an ether-based thermoplastic polyurethane elastomer. The obtained ether-based thermoplastic polyurethane elastomer had a JIS A hardness of 85.
An elevator rope was obtained in the same manner as in Example 1 except that this ether-based thermoplastic polyurethane elastomer was used instead of the ether-based thermoplastic polyurethane elastomer described in Example 1.

<Example 5>
Similar to Example 1 except that 9.1% by mass of titanium oxide was added to the ether-based thermoplastic polyurethane elastomer described in Example 2 instead of the ether-based thermoplastic polyurethane elastomer described in Example 1. Thus, an elevator rope was obtained.

<Example 6>
Instead of the ether-based thermoplastic polyurethane elastomer described in Example 1, 4.8% by mass of glass fiber (fiber length of about 1 mm) added to the ether-based thermoplastic polyurethane elastomer described in Example 2 was used. An elevator rope was obtained in the same manner as in Example 1.

<Example 7>
Instead of the ether-based thermoplastic polyurethane elastomer described in Example 1, the same procedure as in Example 1 was used except that 9.1% by mass of talc was added to the ether-based thermoplastic polyurethane elastomer described in Example 2. Thus, an elevator rope was obtained.

<Comparative Example 1>
An elevator rope was obtained in the same manner as in Example 1 except that only the ether-based thermoplastic polyurethane elastomer described in Example 1 was used without using blocked isocyanate.

<Comparative Example 2>
An elevator rope was obtained in the same manner as in Example 1 except that the blocked isocyanate was not used and the JIS A hardness of the ether-based thermoplastic polyurethane elastomer described in Example 1 was changed from 85 to 95.

<Comparative Example 3>
An elevator rope was obtained in the same manner as in Example 3 except that only the ether-based thermoplastic polyurethane elastomer described in Example 3 was used without using blocked isocyanate.

[JIS A hardness of resin coating layer]
According to JIS K7215, the durometer A hardness was measured using a type A durometer. The results are shown in Table 1.

[Measurement of glass transition temperature (Tg) of resin coating layer]
The glass transition temperature (Tg) of the resin coating layer was measured as follows. A resin coating layer-forming composition having the same composition as the resin coating layer used in each of the examples and comparative examples was supplied to an injection molding machine, molded into a 100 mm × 100 mm × 2 mm thick flat plate, and heated at 110 ° C. for 2 hours. Thereafter, a test piece of 50 mm × 10 mm × thickness 2 mm was cut out from the center. Using a viscoelastic spectrometer DMS120 manufactured by Seiko Instruments Inc., the loss elastic modulus of the test piece was measured under the conditions of deformation mode bending mode, measurement frequency 10 Hz, heating rate 2 ° C./min, and excitation amplitude 10 μm. The peak temperature of the elastic modulus was Tg. The results are shown in Table 1.

[Measurement of rope friction coefficient]
(1) Measuring Method at Minute Sliding Speed and Normal Driving Sliding Speed FIG. 2 is a conceptual diagram of an apparatus for measuring a friction coefficient in a minute sliding speed region. As shown in FIG. 2, the elevator rope 1 obtained in the example and the comparative example is wound around the sheave 2 by 180 degrees, one end is fixed to the measuring device 3, the other end is connected to the weight 4, and the elevator rope is used. Rope 1 was tensioned. Here, when the sheave 2 is rotated clockwise at a predetermined speed, the rope tension (T ₂ ) on the fixed side is loosened by the frictional force generated between the elevator rope 1 and the sheave 2, and the rope tension on the weight side ( A difference in tension occurs with respect to T ₁ ). The rope tension (T ₁ ) on the weight side and the rope tension (T ₂ ) on the fixed side were measured by a load cell provided at the connecting portion between the rope and the weight. The minute slip speed is defined as 1 × 10 ⁻⁵ mm / sec, the slip speed during normal operation is defined as 1 mm / sec, T ₁ and T ₂ (where T ₁ > T ₂ ), rope winding angle θ (= 180 degrees) The coefficient of friction K ₂ (= 1.19) determined by the shape of the sheave groove was substituted into the following equation 1 to obtain the friction coefficient between the elevator rope 1 and the sheave 2. The results are shown in Table 1. All measurements were performed at an ambient temperature of 25 ° C.

(2) Measuring Method in Large Sliding Speed Range for Emergency Stop FIG. 3 is a conceptual diagram of an apparatus for measuring a friction coefficient in a large sliding speed range for emergency stopping. The elevator rope 1 obtained in the example and the comparative example was wound around the drive sheave 5 by 180 degrees, one end thereof was connected to the weight 4a, and the other end was connected to the weight 4b having a mass larger than that of the weight 4a. Here, the weight 4a is raised by rotating the driving sheave 5 clockwise, and when the rope speed reaches 4 m / s, the driving sheave 5 is suddenly stopped, and the elevator rope 1 is slipped with respect to the driving sheave 5. It was. At that time, the minimum deceleration α of the weight 4a, the tension on the weight 4a side (T ₃ ), and the tension on the weight 4b side (T ₄ ) are measured by the load cell provided at the connecting portion of the rope and the weight, and these values are measured. Substituting into the following formula 2, the minimum coefficient of friction during slip was determined. Table 1 shows the test results. All measurements were performed at an ambient temperature of 25 ° C.

Here, K ₂ is the same as the value used in the measurement method in the minute slip velocity region, g is gravity (= 9.80665 m / s ² ), and θ is the rope winding angle (= 180 degrees).

  Rope friction coefficient measured by each measuring method is less than 0.15, Δ is 0.15 or more and less than 0.2, ○ is 0.2 or more and less than 0.25, 0.25 or more A value of 0.6 or less was rated as ◎. However, none of the examples and comparative examples showed a coefficient of friction exceeding 0.6.

As can be seen from the results in Table 1, the micro-slip speed range (1 × 10 ⁻⁵ mm / s) using the elevator ropes obtained in the examples and comparative examples and the friction coefficient at the time of emergency stop are as follows. It showed a tendency to lower than the friction coefficient.
In the elevator ropes obtained in the examples, the frictional coefficient at the minute slip speed range and the emergency stop was 0.15 or more. From the comparison between the results of Example 1 and the results of Examples 2-3, a thermoplastic polyurethane elastomer obtained by reacting a mixture of diol and triol or a high molecular weight polyol mixture having a functional group number of 2.1 or more and less than 3 was blocked. Fluctuation coefficient variation can be reduced by using together with isocyanate. From the comparison of the results of Example 1 and Examples 5 to 7, the addition of an inorganic filler to the thermoplastic polyurethane elastomer can reduce the variation of the friction coefficient. In particular, it was found that the fluctuation of the friction coefficient can be further reduced by adding glass fiber which is a fibrous inorganic filler or talc which is a plate-like inorganic filler. On the other hand, all of the elevator ropes obtained in the comparative examples have a problem that the friction coefficient at the time of an emergency stop is too low.

  1 Elevator rope, 2 sheave, 3 measuring device, 4, 4a, 4b Weight, 5 drive sheave.

Claims (5)

Rope body, and covers the outer periphery of the rope main body, a manufacturing method of Rue elevators rope includes a resin coating layer made of a molded product tree fat coating layer forming composition,
A thermoplastic polyurethane elastomer and a blocked isocyanate obtained by reacting an isocyanate compound having two or more isocyanate groups in one molecule with a blocking agent, the molded article of the resin coating layer forming composition has a JIS A hardness of 98 or less. And the step of preparing the resin coating layer-forming composition by mixing within a range where the glass transition temperature is -20 ° C. or less, and coating the rope body with the resin coating layer, and then the thermoplastic polyurethane with the blocked isocyanate And a step of heating to 100 ° C. to 120 ° C. to promote crosslinking of the elastomer . The thermoplastic polyurethane elastomer is a chain composed of a mixture of an aromatic diisocyanate, a high molecular weight polyol having an average molecular weight of 450 to 4000 and a functional group number 2, a diol having an average molecular weight of 60 to 450 and a triol having an average molecular weight of 60 to 450. The method for producing an elevator rope according to claim 1, wherein the method is obtained by reacting with an extender. The thermoplastic polyurethane elastomer reacts with an aromatic diisocyanate, a high molecular weight polyol having an average molecular weight of 450 or more and 4000 or less and a functional group number of 2.1 or more and less than 3, and a chain extender comprising a diol having an average molecular weight of 60 or more and less than 450. The method for manufacturing an elevator rope according to claim 1, wherein the method is obtained . The method for manufacturing an elevator rope according to any one of claims 1 to 3, wherein an inorganic filler is further mixed in the resin coating layer forming composition. The method for manufacturing an elevator rope according to claim 4, wherein the inorganic filler is fibrous or plate-like.

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