JP2003322218A - Polyurethane belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane belt with such a small friction coefficient that less noise is generated between the belt and a pulley, in which deterioration of polyurethane is less generated by metal ions even in environments where it gets in contact with metal as in case of carrying coins. <P>SOLUTION: This polyurethane belt comprises a toothed belt 1 of polyurethane in which core wires 3 are embedded in a length direction in a belt main body. The belt main body is composed of polyurethane resin composition blended with carbon nanotubes, so that the friction coefficient is so small because of existence of the carbon nanotubes that less noise is generated between the belt and the pulley. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane belt, and more particularly, to a polyurethane belt which is prevented from being deteriorated by a metal, and further, is prevented from generating a sound and is improved in durability.

[0002]

2. Description of the Related Art Conventionally, rubber or polyurethane has been used as a material for power transmission belts and conveyor belts for conveying coins and the like. Rubber had the problem of poor appearance, but on the other hand, polyurethane belts have a better appearance than rubber, and because they do not have the drawback of dropping abrasion debris around, the range of use is It covers a wide range.

However, polyurethane is originally decomposed and degraded by the supply of heat, light, or other energy from the outside. At that time, when heavy metals such as Mn, Co, Cu, Fe, and Pb exist in the decomposition and deterioration reaction system in the form of ions or complex compounds, they have a catalytic action to significantly accelerate by participating in the reaction.

However, polyurethane belts are often used in contact with metal. For example, when carrying a coin on the back with a polyurethane belt, or with a polyurethane belt in which protrusions are integrally molded on the back and a coin is placed between the protrusions and carrying a polyurethane belt, it always contacts metal. There has been a problem that a coin cannot be transported due to a crack on the back surface that comes into contact with the coin or a protrusion that comes into contact with the coin.

Further, in the case of a polyurethane toothed belt, when it is used as a carriage belt of a printer or a paper feed of a facsimile at a place such as an office where quietness is required, it meshes with a pulley. Under a circumstance, a “creepy” sound or “ringing”
There was a sound.

Polyurethane V used for NC lathe etc.
Regarding the belt, if the belt separates from the pulley when the belt and pulley are engaged, or if the friction coefficient of the belt is too high, the belt sticks to the pulley and becomes difficult to separate. Was. Even if the alignment (parallelism) of the pulleys was a little misaligned, the polyurethane resin had a high friction coefficient, and a similar squeaking noise was produced.

The V-ribbed belt made of polyurethane is used as a belt for moving the rubbing machine of the massaging machine up and down. However, when the massaging machine is used, a "twitching" sound may be generated while the massaging machine is being moved. It was annoying to me. This phenomenon also occurs when the belt is separated from the pulley or when the alignment of the pulley is misaligned, as in the case of the polyurethane V belt.

When a polyurethane V-ribbed belt is used in a microcomputer-controlled fully automatic washing machine or dryer, static electricity generated by friction of the belt with a pulley during belt operation charges the microcomputer, and electronic circuits in the microcomputer are charged. There was a case where an error occurred and a microcomputer malfunctioned.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a polyurethane belt having a small friction coefficient which makes it difficult to generate sound between the belt and the pulley.
Another object of the present invention is to provide a small polyurethane belt in which deterioration of polyurethane due to metal ions is unlikely to occur even in the environment where it comes into contact with a metal, such as when a coin is conveyed.

[0010]

That is, the invention according to claim 1 of the present application is a polyurethane belt comprising a belt main body and a core wire embedded along the longitudinal direction of the belt, wherein the belt main body is made of carbon nanotubes. This is a polyurethane belt composed of a blended polyurethane resin composition. Due to the presence of carbon nanotubes, the friction coefficient is small, and it is difficult for sound to be generated between the belt and the pulley.

The invention according to claim 2 of the present application is a polyurethane belt in which carbon nanotubes are impregnated with oil and fat, and since oil and fat are deposited on the belt surface for a long time,
The coefficient of friction of the belt surface is continuously reduced.

The invention according to claim 3 of the present application is a urethane belt in which a metal deactivator is further mixed in the belt main body, and in addition to the effect of claim 1, polyurethane is further provided on the back surface or the back surface of the polyurethane belt. Even when a coin is conveyed by the protrusion formed integrally with the belt, it is possible to prevent the polyurethane from deteriorating due to the metal coming into contact with the polyurethane.

In the invention according to claim 4, the metal deactivator is a polyurethane belt in which a hindered phenol structure is also used in the structure of the hydrazine compound, and the metal deactivator is hindered in the structure of the hydrazine compound. By using the phenol structure in combination, in addition to the effect of suppressing the deterioration of the polyurethane from metal ions, the hindered phenol structure can prevent the deterioration of the polyurethane from the effects of heat and oxygen due to the antioxidant function.

The invention according to claim 5 of the present application is a urethane belt using a twisted cord made of polyarylate fiber filaments as the core wire, and by selecting the polyarylate fiber cord as the core wire, high strength and high modulus can be obtained. In addition, it is possible to provide a polyurethane belt having excellent dimensional stability over time and flexibility.

The invention according to claim 6 of the present application is the polyurethane belt which is a toothed belt having a plurality of tooth portions arranged at predetermined intervals along the length direction and a back portion in which the core wire is embedded. .

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. 1 is a polyurethane toothed belt of the present invention, (a) is a partially broken perspective view, (b) is a sectional view,
Tooth 5 and groove 6 are alternately arranged at a constant pitch in the longitudinal direction of the belt, and a core wire 3 made of polyarylate fiber, glass fiber, polyester fiber, aramid fiber or the like is embedded on the belt pitch line. .

FIG. 2 is a perspective view of the polyurethane V-belt of the present invention, FIG. 3 is a perspective view of the polyurethane V-ribbed belt of the present invention, and FIG. 4 is a perspective view of the polyurethane truncated V-ribbed belt of the present invention. Is. In the friction transmission belt of the present invention, a tension rope 3 made of polyarylate fiber, polyester fiber, aramid (trade name Kevlar) fiber or the like is spirally embedded in the belt body in the belt longitudinal direction, and the belt body is also provided. The inner peripheral surface of 1 has at least one V extending in the belt circumferential direction.
The shape protrusion is formed integrally with the belt body 1.

Here, the polyurethane resin composition constituting the belt main body is obtained by casting and heating a liquid urethane raw material. Generally, the molding method is to use a polyol, a catalyst, a chain extender, a pigment or the like. A one-shot method in which a mixed premix liquid and a solution containing an isocyanate component are mixed, and this is cast to perform a curing reaction,
There is a prepolymer method of reacting an isocyanate with a polyol in advance, mixing a prepolymer obtained by modifying a part of the isocyanate with a polyol and a curing agent, and performing a crosslinking reaction, but in the present invention, the prepolymer method is preferably used. To be

The isocyanate is not limited, but aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, and modified products thereof can be used. Specifically, toluene diisocyanate (TDI), methylene diisocyanate (M
DI), xylylene diisocyanate (XDI), naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and the like.
And MDI are preferably used.

Examples of polyols include ester-based polyols, ether-based polyols, acrylic polyols, polybutadiene polyols, and mixed polyols thereof. The ether-based polyols include polyethylene ether glycol (PEG), polypropylene ether glycol (PPG), polytetramethylene ether glycol (PTMG), and the ester-based polyols include polyethylene adipate (PPG).
Examples thereof include EA), polybutylene adipate (PBA), polyhexamethylene adipate (PHA), poly-ε-caprolactone (PCL), and the like.

As the curing agent, amine compounds which are primary amines, secondary amines and tertiary amines are used, and specifically, 1,4-phenylenediamine, 2,6-diaminotoluene and 1,5-naphthalene. Diamine, 4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4 '
-Diaminodiphenylmethane (hereinafter referred to as MOCA),
3,3'-dimethyl-4,4'-diaminodiphenylmethane, 1-methyl-3,5-bis (methylthio) -2,
6-diaminobenzene, 1-methyl 3,5'-diethyl-2,6-diaminobenzene, 4-4'-methylene-bis- (3-chloro-2,6-diethylaniline), 4,
4'-methylene-bis- (ortho-chloroaniline),
4,4'-methylene-bis- (2,3-dichloroaniline), trimethylene glycol di-para-aminobenzoate, 4,4'-methylene-bis- (2,6-diethylaniline), 4,4 ' -Methylene-bis- (2,6-
Diisopropylaniline), 4,4'-methylene-bis- (2-methyl-6-isopropylaniline), 4,4
′ -Diaminodiphenyl sulfone and the like can be used.

In addition to the above components, additives such as a plasticizer, a pigment, a defoaming agent, a filler, a catalyst and a stabilizer can be added. As the plasticizer, dioctyl phthalate (DOP), dibutyl phthalate (DBP), dioctyl adipate (DOA), tricresyl phosphate (TC) are generally used.
P), chlorinated paraffin, dialkyl phthalate, etc. can be used.

As the catalyst, an organic carboxylic acid compound which is an acid catalyst is used, and specifically, aliphatic carboxylic acids such as azelaic acid, oleic acid, sebacic acid and adipic acid, and aromatic compounds such as benzoic acid and toluic acid. Group carboxylic acids are used. In addition, amine compounds represented by triethylamine, N, N-dimethylcyclohexylamine, triethylenediamine, organometallic compounds represented by stannas octoate, dibutyltin dilaurate, and dioctyltin mercaptide are appropriately used.

Carbon nanotubes are added to the polyurethane resin composition. The carbon nanotube has a diameter of about 0.5 to 10 nm and a length of 0.5 to 10 μm.
It is a cylindrical material made of only m carbon atoms, and has a multilayer or single layer. Carbon nanotubes are added in an amount of 5 to 50% by mass. It is preferable to increase the amount of carbon nanotubes added.

Further, a metal deactivator is added to improve the deterioration due to metal ions. The metal deactivators are hydrazine-based, bisphenol-based, phosphite-based, and triazole-based, and are N, N'-bis [3- (3,5-di-t-butyl-4-hydroxy). Phenyl) propionyl] hydrazine, 2,2'-oxamidobis- [ethyl 3- (3,5-di-t-butyl-4]
-Hydroxyphenyl) propionate], 9,10-
Dihydro-9oxa-10 phosphaphenanthrene-1
0-oxide 3,4,5,6-dibenzo-1,2-oxaphosphane-2-oxide, 3- (N-salicyloyl) amino-1,2,4-triazole and the like can be mentioned. These may be used alone or in a composite system. The addition amount of the metal deactivator is 0.01
-10 mass% is preferred. This is because if the addition amount is less than 0.01% by mass, the wet heat resistance is deteriorated, and if the addition amount exceeds 10% by mass, the physical properties of the polyurethane are deteriorated, which is not preferable.

More preferably, the above metal deactivator is
A compound in which a hindered phenol structure is used in combination in the structure of the compound, and N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, or 2,2'- Oxamide bis- [ethyl 3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] also exerts an antioxidative ability, and is more effective in preventing deterioration when transporting metals such as coins in a more severe wet heat environment.

Next, the steps of preparing the urethane raw material will be described. Liquid A prepared by adding a defoaming agent and a plasticizer to the urethane prepolymer previously reacted with the isocyanate and the polyol is prepared and stored at 50 to 85 ° C. Further, a liquid B in which a curing agent is completely dissolved at an ambient temperature of 120 ° C. or higher is prepared. When the catalyst is added to the urethane raw material, it is preferable to stir and mix it with the liquid B in advance.

As a belt molding method, as in the conventional manufacturing method, the core wire is spirally wound around the mold,
The solution A and solution B are stirred and mixed, poured into a mold, heated under a certain condition to be cross-linked to produce a belt sleeve, and then cut into a predetermined width to produce a belt. .

The above-mentioned molding method is not particularly limited,
Ordinary casting method, or by rotating the inner mold and the outer mold at a predetermined number of revolutions, after casting the above mixture, centrifugal force is used to fill the cavity between the inner mold and the outer mold with a liquid. It may be a centrifugal molding method in which crosslinking is carried out at the temperature. As the mold used for the polyurethane toothed belt, at least an outer mold and an inner mold are used, and the inner peripheral surface of the outer mold is usually flat. As the inner mold, a cylindrical or columnar mold having a plurality of grooves arranged in the longitudinal direction is used.

Further, the polyurethane resin composition may be added with short fibers impregnated with oil and fat, and the short fibers may be deposited on the surface to reduce the friction coefficient of the belt. Here, the types of fats and oils include lard (pork fat) and beef tallow as animal solid fats, and linseed oil, soybean oil, sesame oil, rapeseed oil, olive oil, castor oil, peanut oil, palm oil as vegetable solid fats, There is coconut oil. Oils and fats are preferable because they exude to the surface of the belt and reduce the friction coefficient of the surface of the belt. By impregnating the short fibers with the oil and fat, even after the short fibers deposited on the belt surface disappear, the oil and fat exude from the short fibers and deposit on the belt surface, so that the friction coefficient of the belt surface is continuously lowered.

The short fibers to be added include nylon, polyester, aramid, cotton, glass, etc. The length of these short fibers is 0.05 to 5 mm and the fiber diameter is 10 to 30.
μm, which includes what is called flocs. If the length of the short fibers is shorter than 0.05 mm, even if they appear on the surface of the belt, they will disappear immediately due to wear of the conveyed object or the pulley, and if the length exceeds 5 mm, the short fibers will become entangled with each other and thus will be independent. Will not be dispersed, and the dispersed state will be non-uniform, and it will be difficult to concentrate on the outer mold surface even if centrifugal force is applied.

As a method for adding the short fibers impregnated with fats and oils to the urethane prepolymer, first, the short fibers are immersed in a predetermined amount of fat and oil in advance, and when the short fibers are sufficiently impregnated with the fats and oils, the urethane prepolymer is added. Short fibers impregnated with oil and fat are added to it, and then a curing agent is further mixed and stirred, and then immediately cast into a mold and crosslinked at a predetermined temperature for a certain period of time, then demolded to form a belt sleeve, and then to a predetermined width. Cut to obtain a polyurethane toothed belt. A polyurethane friction transmission belt can be obtained in a similar manner.

As the mold used for the polyurethane toothed belt, at least an outer mold and an inner mold are used, and the inner peripheral surface of the outer mold is usually flat. As the inner mold, a cylindrical or columnar mold having a plurality of grooves arranged in the longitudinal direction is used.

In order to deposit the short fibers on the surface of the belt, a forming method is adopted in which the short fibers are collected and localized in the outer mold by centrifugal molding. Here, if the portion for reducing the friction coefficient is a V-shaped portion or a V-ribbed portion that is a friction transmission portion, or a tooth portion if it is a toothed belt, a groove for forming the V-shape, V-rib shape, or tooth shape on the outer die. Carved and reverse molded. This reverse-formed belt becomes a polyurethane belt having a V-shaped portion, a V-ribbed portion, and a tooth portion for transmitting power to the inside by inverting the inside and the outside after cutting the belt. Also,
When it is necessary to make the back side of the belt have some slipperiness when coins are conveyed on the back side of the belt, a V-shaped portion, a V-ribbed portion, or a groove for forming a tooth shape is formed on the inner die and the outer die is The friction coefficient on the back surface of the belt can be lowered by localizing the short fibers on the back surface of the belt by localizing the short fibers on the outer surface of the outer mold surface by normal molding as a flat surface.

As a molding method when carbon nanotubes are added, a molding method in which carbon nanotubes are collected outside by centrifugal molding and localized is adopted. As described above, the mold is provided with a groove for molding the shape for power transmission in either the inner mold or the outer mold, and imparts electrical conductivity to the inside of the belt according to the application, or to the back side of the belt. Make sure to select either conductivity.

Further, by adding carbon nanotubes impregnated with oil and fat to the polyurethane resin composition and depositing carbon nanotubes on the belt surface, the electrical resistance value of the belt surface can be lowered and the belt can be made electrically conductive. it can. Further, since the carbon nanotubes are impregnated with oil and fat, the oil and fat exude from the carbon nanotubes dispersed on the belt surface, and the friction coefficient on the belt surface is lowered, so that sound generation can be continuously suppressed.

FIG. 7 shows a cross-sectional view of steps for producing the polyurethane belt of the present invention. In this figure, the mold is the bottom mold 1
8, a lid mold 13, an outer mold 15, and an inner mold 14, and an inner mold 14
The lid mold 13 is fitted to the inner mold 14 by a boss 16. Then, the assembled mold is installed in a centrifugal molding machine, and when the polyurethane undiluted solution is injected while rotating at a predetermined number of revolutions, the undiluted polyurethane solution L is obtained from the inner space of the inner mold.
A polyurethane belt molded body is produced by filling the cavity between the inner mold and the outer mold through 7 and curing.

Further, a lubricant selected from graphite, ethylene tetrafluoride resin powder, paraffin, molybdenum disulfide and the like may be mixed into the polyurethane resin composition and concentrated in only the back surface layer of the belt. The molding method is centrifugal molding, and the lubricant selected from the above is locally concentrated on the outer mold surface by centrifugal force. in this case,
As in the case of adding carbon nanotubes, the mold should have a groove for molding the shape for power transmission in either the inner mold or the outer mold to reduce the friction coefficient inside the belt according to the application. , Or to reduce the friction coefficient on the back side of the belt.

The amount of lubricant added is 0.01 to 10
Add mass%. Here, if the amount of the lubricant is less than 0.01% by mass, the effect of the lubricant is not exerted and the friction coefficient is not lowered. On the other hand, if the amount of the lubricant exceeds 10% by mass, the coefficient of friction does not decrease any more and the physical properties of the polyurethane are only deteriorated, which is not preferable. Here, it is also possible to use a low friction polyurethane belt to which electrical conductivity is imparted by using oil and fat, carbon nanotubes and a lubricant together.

[0040]

EXAMPLES Examples 1 to 4 and Comparative Examples 1 and 2 Belts were produced with the formulations shown in Table 1 as Examples 1 to 4 and Comparative Examples 1 and 2. 3,3'-dichloro-4,4'-diaminodiphenylmethane as a curing agent and Irganox MD102 manufactured by Ciba-Geigy Co. as a metal deactivator.
4. DOP was used as a plasticizer, an acid catalyst was used as a catalyst, and carbon nanotubes impregnated with palm oil, molybdenum disulfide, and short fibers (6 nylon fibers) were used. As the belt, an S2M type toothed belt was manufactured. First, the prepolymer and DOP were mixed in advance and stored under environmental conditions of 60 ° C. Next, the curing agent is added to the prepolymer 1
12 parts by mass with respect to 00 parts by mass, and 1 part by mass of the acid-based catalyst with respect to 100 parts by mass of the prepolymer, and mixed at 120 ° C.
It was stored under the following environmental conditions. Further, the metal deactivator was heated and dissolved, and stored under an environmental condition of 200 ° C. When the above-mentioned short fibers impregnated with palm oil, carbon nanotubes impregnated with palm oil, and molybdenum disulfide are added, the prepolymer and DOP are mixed in advance, stirred for 2 hours in a ball mill, and then defoamed. I was there.

[0041]

[Table 1]

Then, an inner die having a tooth groove formed in the longitudinal direction for holding the core wire is attached to a spinning device, and the inner die is rotated to form a polyarylate fiber filament (Vectran HT440T / 1 manufactured by Kuraray Co., Ltd.) as the core wire. ) Is untreated and twisted to give a total of 440 denier,
A twisted cord having a twist number of 40 times / 10 cm was spirally wound. Then, the inner mold wound with the core wire was installed in the centrifugal casting machine placed in a high temperature tank of 120 ° C., and then the outer mold having a flat inner peripheral surface. Then, the mold in the centrifugal molding machine was rotated at 4500 rpm. Next, the above prepolymer, DOP, curing agent, and metal deactivator were mixed and sufficiently stirred with a stirrer to prepare a blend.

The stirred formulation was cast into a rotating inner mold. Then, the centrifugal molding machine was rotated at 4500 rpm for 30 minutes. After that, the outer mold and the inner mold are disassembled and the belt sleeve attached to the mold is taken out and cut into a predetermined width S2M
A type of toothed belt was obtained.

Example 1 is a belt in which carbon nanotubes are concentrated on the tooth surface of the belt. As a result, the belt was provided with conductivity. Furthermore, the palm oil impregnated in the carbon nanotubes exudes and deposits on the surface of the tooth of the belt, the friction coefficient is lowered, and the pronunciation can be suppressed.

Example 2 was a belt in which carbon nanotubes were concentrated and localized on the tooth surface of the belt and molybdenum disulfide was localized on the back surface of the belt. Conductivity can be imparted to the belt, and the friction coefficient on the back side of the belt is also reduced, so that the abrasion resistance on the back side of the belt is improved when articles are conveyed on the back side of the belt. Furthermore, since the palm oil is deposited on the belt tooth surface, the pronunciation can be suppressed.

In Example 3, a carbon nanotube was formed on the tooth surface of the belt and short fibers were concentrated and localized on the back surface of the belt. The belt can be made electrically conductive, and the back surface of the belt has a reduced friction coefficient, which improves the wear resistance of the back surface of the belt. Further, since palm oil impregnates both carbon nanotubes and short fibers, it is possible to continuously reduce the friction coefficient on the tooth surface and the back surface of the belt.

In Example 4, a carbon nanotube was formed on the tooth surface of the belt and short fibers and molybdenum disulfide were concentrated and localized on the back surface of the belt. In addition to the belt of Example 3, both short fibers and molybdenum disulfide are localized in the back surface of the belt, so that the wear resistance of the back surface of the belt is further improved.

Next, the coefficient of friction was measured using the belts of Examples 1 to 4 and Comparative Examples 1 and 2. As the method of measuring the friction coefficient, the friction coefficient of the belt was measured with the layout shown in FIG. A load cell (not shown) was connected to one end of the belt 20, and a load 24 was wound around the other end of the belt 20 at an angle of 45 °. Examples 1 to 4 and Comparative Examples 1 and 2
A flat pulley was used as the pulley 22, and the back surface of the belt was wrapped around the flat pulley to measure the friction coefficient. About 30
This is taken as the average of the sum of the maximum value and the minimum value of the load data recorded in the load cell 5 seconds to 15 seconds after the start of measurement, and this data value is used to calculate the friction coefficient ( μ) to obtain the friction coefficient. The results are shown in Table 2. Friction coefficient (μ) = ln (T / P) /0.785 T: Data value (kgf) P: Set load (kgf)

Next, the electric resistance values of the examples and comparative examples were measured. In Examples 1 to 4 and Comparative Examples 1 and 2, the tooth flank of the belt was measured. As the measuring method, the electric resistance value on the belt at a distance of 216 mm was measured with an insulation resistance meter. Applied voltage is 50
It was 0V. The results are shown in Table 2.

Next, the pronunciation tests of Examples 1 to 4 and Comparative Examples 1 and 2 were conducted. As a test condition, an S2M pulley having 32 teeth was used for both the driving and driven pulleys. The belt tension was 1 kgf, the load on the belt was 100 W, and the rotation speed of the drive pulley was 3600 rpm. Then, the distance from the drive pulley was set to 20 mm, and the sound level was measured with an ordinary sound level meter. The results are shown in Table 2.

Next, a bench endurance test was conducted using the examples and comparative examples. As test conditions, in Examples 1 to 4 and Comparative Examples 1 and 2, an S2M pulley having 32 teeth was used as a drive pulley, and an S2M pulley having 60 teeth was used as a driven pulley. The results are shown in Table 2.

[0052]

[Table 2]

It can be seen from Tables 2 and 5 that all Examples have an electric resistance value of less than 10 ¹⁰ Ω and an antistatic effect. In Example 2 and Example 4, the friction coefficient is small due to the effects of adding molybdenum disulfide and short fibers, respectively. Further, it can be seen that the number of flexing is 10 ⁸ or more in all the examples, and the durability is excellent. In Examples 3 and 4, since both the carbon nanotubes and the short fibers were impregnated with palm oil, the amount of palm oil exuding on the tooth surface of the belt was large and the pronunciation was small. It was In addition, the pronunciations of Examples 1 and 2 are smaller than that of the comparative example containing no palm oil.

[0054]

As described above, according to the present invention, the presence of carbon nanotubes has a small coefficient of friction and makes it difficult for sound to be generated between the belt and the pulley. Even when coins are conveyed on the back surface of the belt or on the protrusions formed integrally with the polyurethane belt on the back surface, it is possible to prevent the polyurethane from deteriorating due to the metal coming into contact with the polyurethane, and to improve the durability of the belt. is there.

[Brief description of drawings]

FIG. 1 is a polyurethane toothed belt of the present invention,
(A) is a partially broken perspective view and (b) is a sectional view.

FIG. 2 is a perspective view of a polyurethane V-belt of the present invention.

FIG. 3 is a perspective view of a polyurethane V-ribbed belt of the present invention.

FIG. 4 is a perspective view of a polyurethane truncate V-ribbed belt of the present invention.

FIG. 5 is a cross-sectional view of a polyurethane V-ribbed belt of the present invention.

FIG. 6 is a cross-sectional view showing a step of producing a polyurethane belt of the present invention.

FIG. 7 is a layout diagram in which the coefficient of friction of a polyurethane belt is measured.

[Explanation of symbols]

1 Polyurethane toothed belt 2 back 3 cores 4 canvas 5 teeth 6 tooth bottom 7 Polyurethane toothed belt 8 Polyurethane V belt 9 V-shaped protrusion 10 back cog 11 Polyurethane V-ribbed belt 12 Truncate V-ribbed belt made of polyurethane

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Claims (6)

[Claims] 1. A polyurethane belt comprising a belt body and a core wire embedded along the longitudinal direction of the belt, wherein the belt body is composed of a polyurethane resin composition containing carbon nanotubes. Made of polyurethane belt. 2. The polyurethane belt according to claim 1, wherein the carbon nanotubes are impregnated with oil and fat. 3. The polyurethane belt according to claim 1, further comprising a metal deactivator added to the belt body. 4. The metal deactivator additionally uses a hindered phenol structure in the structure of the hydrazine compound.
Polyurethane belt as described in. 5. The polyurethane belt according to claim 1, wherein a twisted cord made of polyarylate fiber filament is used as the core wire. 6. The polyurethane according to claim 1, wherein the belt is a toothed belt having a plurality of tooth portions arranged at predetermined intervals along the length direction and a back portion in which a core wire is embedded. Made belt.