JP3307836B2 - Endless belt for transporting paper sheets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic ticket gate, a cash depositing machine, a money changer, an automatic ticketing machine, etc., in which bills, magnetic cards, tickets and the like are sandwiched between opposed belts. The present invention relates to an endless belt for transporting paper sheets for transporting in multiple directions by a pinching force between the belts.

[0002]

2. Description of the Related Art Conventionally, in an automatic ticket gate, a cash depositing machine, a money changer, an automatic ticket issuing machine, and the like, bills, magnetic cards, tickets, and the like are sandwiched between belts arranged opposite to each other so that the belts are held. It is conveyed by the pinching force between them. That is, for example, as shown in FIG.
And 02 are stretched around a pair of pulleys 03a, 03b and 04a, 04b, respectively, and are arranged opposite to each other. It is conveyed by the pinching force.

As a belt of this kind, a bill, a magnetic card, a ticket, and the like are transported smoothly in the apparatus. Has sufficient tearing force so that it does not come into contact with the part, and has high elongation and small initial tension so that the allowable range of the center distance between pulleys can be made large; sufficient durability. It is necessary to have performance. And for this kind of belt,
A belt made of a cylindrical body made of knitted nylon false twisted yarn, etc. is provided in a rubber elastic body such as neoprene rubber, urethane rubber, ethylene propylene diene terpolymer rubber, etc. This is known (see, for example, JP-A-62-16165).

[0004]

However, recently,
Due to the complexity and speed of the transport route due to the downsizing of the equipment, the friction coefficient of the belt surface increases, especially at high temperatures, and the difference in peripheral speed between the belts causes the belt surface to wear and become sticky. As a result, the paper may not be transported smoothly, and furthermore, the paper may adhere to the belt surface.

Accordingly, the present invention has been made in view of such circumstances,
An object of the present invention is to provide an endless belt for transporting paper sheets, which can substantially eliminate the wear of the belt surface and the adhesiveness caused by the wear, and can stably transport the paper sheets for a long period of time.

[0006]

A first aspect of the present invention that achieves the above object is an endless belt for transporting paper sheets that transports paper sheets by sandwiching force between opposed belts. It is obtained from the reaction of a polyol containing poly-ε-caprolactone diol represented by the formula (I) with polyisocyanate, and the average value of the caprolactone chain in the poly-ε-caprolactone diol is controlled to a predetermined range. The molecular weight distribution Mw / Mn of the caprolactone chain portion of the poly-ε-caprolactone diol is 1.5 or less, and the crystallinity of the caprolactone chain is affected by the isocyanate unit containing the urethane bond and R in the following formula (I). An endless belt for conveying paper sheets, comprising a kneaded polyurethane in which is inhibited.

[0007]

Embedded image (Here, [] indicates a caprolactone chain portion, and m
And n indicate the number of chains, and R is a polymerization initiator R (OH)
₂ )

Further, the endless belt for conveying paper sheets of the present invention may have a reinforcing core.

Furthermore, the paper sheet conveying belt of the present invention is
Other than the flat belt, for example, a T-shaped belt for transporting paper sheets or a V-shaped belt for transporting coins may be used.

Here, the polyisocyanate is, for example, 2,6-toluene diisocyanate (TDI),
4,4'-diphenylmethane diisocyanate (MD
I), paraphenylene diisocyanate (PPDI),
It is at least one selected from 1,5-naphthalenediisocyanate (NDI) and 3,3-dimethyldiphenyl-4,4′-diisocyanate (TODI).

The content of the poly-ε-caprolactone diol in the total polyol is desirably 30% by weight or more.

Further, the poly-ε-caprolactone diol is formed using a polymerization initiator comprising ε-caprolactone monomer and the compound having an active hydrogen containing R. Kneading type polyurethane.

Further, the polyol contains, for example, a chain extender in addition to the long-chain diol containing the poly-ε-caprolactone diol.

Further, the polymerization initiator R (OH) ₂ of the R of the poly-ε-caprolactone diol is, for example,
The molecular weight is 500 or less.

The molecular weight of the poly-ε-caprolactone diol is, for example, 800 to 1500.

The polymerization initiator R (OH) ₂ for the poly-ε-caprolactone diol is, for example, a linear glycol having 2 to 12 carbon atoms; neopentyl glycol;
1 carbon atom such as 3-methyl-1,5-pentanediol
At least one selected from the group consisting of diols having 2 or less side chains; and diols having an unsaturated group having 12 or less carbon atoms, such as 3-allyloxy-1,2-propanediol, wherein the caprolactone chain is Is controlled in the range of 3 to 6.

Further, the polymerization initiator R (OH) ₂ of the poly-ε-caprolactone diol is, for example, 1,4-
At least one selected from the group consisting of diols having 12 or less carbon atoms containing an aromatic ring such as bis (hydroxyethoxy) benzene and para-xylene glycol, and alicyclic diols such as cyclohexanediol and cyclohexanedimethanol; The average value of the caprolactone chain is controlled in the range of 4-8.

The polymerization initiator R (OH) ₂ of the poly-ε-caprolactone diol includes, for example, those having a molecular weight distribution.

The polymerization initiator R (OH) ₂ of the poly-ε-caprolactone diol is, for example, one formed from at least one selected from the group consisting of polycarbonate diol, polyester diol and polytetraoxyethylene diol. It is.

The glass transition temperature Tg of the kneaded polyurethane is desirably -20 ° C. or lower.

The kneaded polyurethane used in the present invention is:
It can be obtained by reacting a polyol with a polyisocyanate.

Here, the polyol used in the present invention uses a poly-ε-caprolactone diol as a main component. Here, the poly-ε-caprolactone diol is obtained by ring-opening polymerization of ε-caprolactone in the presence of a polymerization initiator having active hydrogen, and can be represented by the above formula (I). In the present invention, the average value of the caprolactone chain (the average value of the following m and n) is within a predetermined range, and the molecular weight distribution Mw / Mn of the caprolactone chain portion is extremely limited to 1.5 or less. Is used.

As described above, the average of the caprolactone chain of the poly-ε-caprolactone diol used in the present invention is set to a predetermined range, for example, 3 to 6 or 3 to 8 because of the caprolactone chain portion and the polyurethane bond. In the kneaded polyurethane of the present invention, in a normal state where no strong stress is applied, a caprolactone chain part originally having strong crystallinity becomes an amorphous state due to an isocyanate unit constituting a urethane bond and R in the above formula. The reversible state in which the caprolactone chain shows its original oriented crystallinity and contributes to the strength in an unusual state where the material is elastic as a whole while maintaining its amorphous state, but in a non-normal state where it is broken by a force such as tension. Is to maintain. Further, the reason why the molecular weight distribution Mw / Mn of the caprolactone chain portion is 1.5 or less is to limit the amount of the caprolactone chain having a larger number than the predetermined range. That is, although the caprolactone chain varies depending on R, for example, when it is larger than 6 or 8, it becomes easy to crystallize in a stressed state, particularly in a state stored at a low temperature, and when crystallization starts in this portion, This is because, for example, a portion having a caprolactone chain of 3 to 6 or 3 to 8 is easily crystallized. This low-temperature crystallization has a serious defect in the functions of the elastomer such as viscoelasticity and high friction coefficient, and has a drawback that the use environment and the storage environment are greatly restricted. On the other hand, when the caprolactone chain is small, the crystallinity is too small to form the reversible state described above. The range in which this reversible state cannot be formed differs depending on the type of R in the above formula. When R is derived from, for example, an aliphatic diol, it is not preferable that the number of chains be 2 or less. In the case where R is derived from a polymer, the number of chains is preferably 3 or less.

In the present invention, by using the specific kneaded polyurethane as described above, the occurrence of tackiness due to the abrasion of the belt surface is reduced, and the occurrence of troubles or cracks in the conveyance state is prevented. In addition, stable characteristics are obtained even in a low-temperature environment, and problems such as belt separation and slip between the belt and pulley are prevented.

In the present invention, the polymerization initiator forming the poly-ε-caprolactone diol, that is, the compound constituting the above-mentioned R, has an active hydrogen and forms a diol after ring-opening polymerization. There is no particular limitation as long as it is present, and diols and diamines can be used. However, in order to remarkably exert the effects of the present invention, it is preferable to use a polymerization initiator having no molecular weight distribution, that is, a short-chain initiator. The poly-ε-caprolactone diol formed using such a short-chain initiator is, for example, R
Can be defined as having a molecular weight of 500 or less. Alternatively, the molecular weight of the whole poly-ε-caprolactone diol can be defined as 800 to 1500.

Further, such an initiator affects the crystallinity of the caprolactone chain portion as described above. Therefore, when R is, for example, a linear hydrocarbon, it is necessary to control the average value of the above-mentioned caprolactone chain to 3 to 6, but R has a large steric hindrance such as an aromatic ring or an aliphatic ring. When it is derived from the initiator and greatly affects the crystallinity of the caprolactone chain portion, the average value of the caprolactone chain may be controlled to 4 to 8. That is, in the present invention, the average value of the caprolactone chain is appropriately controlled to a predetermined value according to the type of the polymerization initiator.

Examples of short-chain initiators that can be used in the present invention include ethylene glycol, thiodiethanol,
Linear glycols having 2 to 12 main chain elements, such as propylene glycol and butylene glycol; diols having a side chain having 12 or less carbon atoms, such as neopentyl glycol and 3-methyl-1,5 pentanediol; Diols having an unsaturated group having 12 or less carbon atoms such as allyloxy-1,2-propanediol; and 12 or less carbon atoms containing an aromatic ring such as 1,4-bis (hydroxyethoxy) benzene and para-xylene glycol And alicyclic diols such as cyclohexanediol and cyclohexanedimethanol.
Of course, these short-chain initiators may be used as a mixture of two or more.

The effects of the present invention can be exerted by using a polymerization initiator having a certain molecular weight distribution, that is, a long-chain initiator. Examples of such long chain initiators include 1,
Examples thereof include polycarbonate diols such as 6-hexane carbonate diol; poeliester diols such as polytetramethylene glycol ether (PTMG); and polyester diols such as butylene adipate diol.

In order to form the poly-ε-caprolactone diol used in the present invention, it is preferable to use a catalyst in addition to ε-caprolactone and a polymerization initiator. As such a catalyst, it is preferable to use a metal compound catalyst containing a halogen or an organic acid group, and examples thereof include stannous halides such as chlorine, bromine and iodine.

In the present invention, as the main component of the polyol,
The above-mentioned specific poly-ε-caprolactone-based diol which is a long-chain polyol is used. In addition, generally used long-chain polyols and chain extenders can be used. As a generally used long-chain polyol, any of a polyester-based polyol and a polyether-based polyol may be used, or a blend or a partially modified one thereof may be used. As the chain extender, for example, ethylene glycol,
Straight-chain glycols having 2 to 12 main chain elements such as thiodiethanol, propylene glycol and butylene glycol; diols having 12 or less carbon atoms such as neopentyl glycol and 3-methyl-1,5-pentanediol Diols having an unsaturated group having 12 or less carbon atoms, such as 3-allyloxy-1,2-propanediol; and containing aromatic rings such as 1,4-bis (hydroxyethoxy) benzene, para-xylene glycol Examples thereof include diols having 12 or less carbon atoms and hydrogenated products thereof. In addition, triols such as trimethylol, stearyl alcohol, and hydroxyethyl acrylate can also be used. In order to remarkably exert the effects of the present invention, it is preferable that the above-mentioned specific poly-ε-caprolactone diol is used as a main component.

The polyisocyanate for forming the polyurethane of the present invention by reacting with such a polyol is 2,6-toluene diisocyanate (TD
I), 4,4'-diphenylmethane diisocyanate (MDI), paraphenylene diisocyanate (PPD)
I), 1,5-naphthalenediisocyanate (ND
I) and 3,3-dimethyldiphenyl-4,4'-diisocyanate (TODI). In particular, 4,4'-diphenylmethane diisocyanate (MD
The use of a polyisocyanate containing I) is preferred because it is known to act as a crosslinking point for peroxide crosslinking.

The mixing ratio of the polyol and the polyisocyanate may be a general ratio, for example, such that the active hydrogen such as the hydroxyl group of the diol and the isocyanate group are almost equimolar. For example, OHV (hydroxyl value: KH
Omg / g) 112, 25 parts by weight of MDI per 100 parts by weight of diol, OHV94: 20.8 parts by weight of MDI per 100 parts by weight of diol, OHV
In the case of 75, MDI is added to 100 parts by weight of diol.
6.7 parts by weight.

The kneading type polyurethane of the present invention is kneaded with a curing agent and heat-cured (crosslinked). Examples of such a curing agent include organic peroxides, sulfur, organic sulfur-containing compounds, and isocyanates for general synthetic rubber. Here, an organic peroxide is generally used, and examples of the organic peroxide include dicumyl peroxide and α, α′-bis (t-butylperoxyisopropyl) benzene. The compounding amount of the organic peroxide is 0.5 to 10 parts by weight, preferably about 1.5 to 5 parts by weight, based on 100 parts by weight of the total of the polyol and the isocyanate. Further, sulfur, the organic sulfur-containing compound can be used as a curing agent when the above-mentioned polymerization initiator or chain extender has an unsaturated bond, for example,
This is the case of 3-allyloxy-1,2-propanediol. Here, the organic sulfur-containing compound is TMTD
Thiuram-based vulcanization accelerators such as (tetramethylthiuram disulfide), TETD (tetraethylthiuram disulfide) and DPTT (dipentamethylenethiuram tetrasulfide); and 4,4′-dithiomorpholine.

When kneading and curing as described above,
Commonly used additives, namely, carbon black, reinforcing materials such as silica, anti-adhesives such as wax,
A plasticizer such as dioctyl phthalate (DOP) is used.

In the polyurethane of the present invention, a hydrolysis inhibitor such as polycarbodiimide may be used in a usual amount of about 0.2 to 3% by weight based on 100 parts by weight of the polyurethane. Since the hydrolysis resistance of the polyurethane member of the present invention is about twice as high as that of the conventional thermosetting kneading type polyurethane, if a hydrolysis inhibitor is used in the same manner as in the conventional case, the hydrolysis resistance is reduced by that much. Is improved, but the amount of addition can be reduced to about half in order to obtain the same level of hydrolyzability as before. Since hydrolysis inhibitors are generally expensive, they can greatly contribute to cost reduction.

Further, as described above, the reinforcing core can be embedded in the belt, if necessary. It is preferable to use a reinforcing core having a high Young's modulus, and examples thereof include cotton yarn, nylon yarn, polyester yarn, aromatic polyamide yarn, and glass fiber. Also,
Nylon false twist yarn knitted by a knitting machine 0.1 mm to 1.
A highly elastic cylindrical body or the like having a thickness of 0 mm can be used as the core body.

The reaction conditions of the kneading type polyurethane are generally 70 ° C. to 150 ° C. for 10 to 120 minutes, and then generally aged at 60 ° C. to 120 ° C. for about 6 to 48 hours. I do. In addition, when an organic peroxide is used as a curing agent, the thermosetting condition is determined based on the decomposition characteristics of the organic peroxide to be used.
It is preferable to set the condition to 0 minutes.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

[Embodiment] A specific embodiment will be described below, but it goes without saying that the present invention is not limited to this.

First, 62 parts by weight of ethylene glycol,
1140 parts by weight of ε-caprolactone were added to the catalyst (SnC
l ₂ ) By reacting appropriately in the presence of 30 ppm, a poly-ε-caprolactone diol having a caprolactone chain of 5 and a molecular weight Mn of 1200 was obtained. This poly-ε
-MDI in 100 parts by weight of caprolactone diol
(4,4'-diphenylmethane diisocyanate) 20
A weight part was added and reacted at 100 ° C. for 6 hours to obtain a millable urethane.

Subsequently, 5 parts by weight of a peroxide crosslinking agent Parkmill D-40 (trade name, manufactured by NOF Corporation), 20 parts by weight of carbon black, and 2 parts by weight of an antioxidant were added to 100 parts by weight of the millable urethane. And 10 parts by weight of process oil were mixed and kneaded with an open roll.

Then, the above kneading type polyurethane was coated on a metal cylindrical mold to a thickness of 0.5 mm by an extruder.
After a cylindrical body made of 6.6 nylon false twisted yarn having a thickness of 0.3 mm was coated thereon and subjected to an adhesive treatment, the kneaded polyurethane was further coated thereon. Further, a bandage-shaped cloth was wound thereon, heated at 160 ° C. for 20 minutes, and then demolded to obtain a cylindrical molded product.

Further, the outer surface of the molded product (the side opposite to the mold contact surface) was polished to obtain an endless belt for conveying paper sheets of this embodiment.

FIG. 1 shows a schematic structure of such an endless belt for transporting paper sheets. As shown in FIG. 1, the endless belt 10 for conveying paper has a structure in which a core 12 is embedded in a belt main body 11.

Also, for comparison, the same has a core,
Commercially available urethane (NOK; Iron Rubber)
A belt using was prepared. Further, similarly, a belt made of chloroprene rubber and a belt made of hydrogenated NBR (HNBR) were produced.

For each of the above belts, various physical properties such as hardness, rebound resilience, breaking strength, breaking elongation, and permanent compression set, and wear characteristics were measured. Table 1 shows the results. The wear characteristics were based on a wear index obtained by an Akron wear test.

[0047]

[Table 1]

The adhesiveness, hydrolyzability, and low-temperature properties of the belt of the example and the belt made of millable urethane of the comparative example were measured as follows. The results are shown in Table 2 below
Shown in

Here, the adhesiveness was measured at room temperature at 1600 rpm.
The adhesion test was performed by rotating the belt under the condition of seconds. In addition, the hydrolyzability was determined based on the change rate of breaking strength and breaking elongation after one month in an atmosphere of 70 ° C. and 95% RH. In addition, low-temperature characteristics are based on actual machine tests at low temperatures.

[0050]

[Table 2]

From the results shown in the table, it can be seen that the paper sheet conveying belt of the present invention has good abrasion characteristics and excellent hydrolytic properties, so that there is no occurrence of tackiness due to abrasion and low temperature characteristics. It is.

[0052]

As described above, the endless belt for conveying paper sheets according to the present invention has a surface treatment layer on its surface, so that the endless belts are opposed to each other with the paper sheets interposed therebetween for a long time. Even when transported over a long period, there is no wear on the belt surface, and there is no stickiness associated with the wear, so that paper sheets can be used stably for a long period of time, and are stable even when used at low temperatures. This shows the characteristics obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of an endless belt for conveying paper sheets according to an embodiment of the present invention.

FIG. 2 is a schematic diagram conceptually illustrating an example of a use state of an endless belt for conveying paper sheets.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Endless belt for conveying paper sheets 11 Belt body 12 Core material

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B65H 5/02 B65G 15/32 C08G 18/42

Claims (2)

(57) [Claims] An endless belt for transporting paper sheets for transporting paper sheets, comprising a poly-ε-polyester represented by the following formula (I):
Obtained from the reaction of a polyol containing caprolactone diol with polyisocyanate, the average value of the caprolactone chain in the poly-ε-caprolactone diol is controlled within a predetermined range, and the caprolactone chain portion of the poly-ε-caprolactone diol Having a molecular weight distribution Mw / Mn of 1.5 or less, and comprising a kneaded polyurethane in which the crystallinity of the caprolactone chain is inhibited by the influence of the isocyanate unit containing the urethane bond and R in the following formula (I). Endless belt for transporting paper sheets. Embedded image (Here, [] indicates a caprolactone chain portion, and m
And n indicate the number of chains, and R is a polymerization initiator R (OH)
₂ ) 2. The endless belt for transporting paper sheets according to claim 1, further comprising a reinforcing core.