JP2004238202A - Carrying rubber roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carrying rubber roller restricted in lowering of a coefficient of friction with the lapse of time, restricted in deterioration due to ozone and swelling due to the fat of hands. <P>SOLUTION: This carrying rubber roller carries a body-to-be-carried, which is led into by manual operation, for feeding is formed of a rubber-like elastic body obtained by blending ethylene-propylene-diene copolymer and nitrile group rubber. Blend rate of the ethylene-propylene-diene copolymer and the nitrile group rubber is set at 2:8 to 7:3, and mass change ratio due to swelling in relation to JIS #3 oil is set at a half or less than the mass change ratio in the case where the rubber elastic body is composed of the only ethylene-propylene-diene copolymer or the nitrile group rubber. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a transport rubber roll used for transporting tickets, cards, bills, and the like held by many people, such as ATMs, automatic ticket gates, ticket vending machines, and the like.

  Conventionally, transport rollers used for automatic ticket gates and the like have been required to have characteristics such as a small change in friction coefficient, no swelling due to hand oil, and little ozone deterioration, and any of polyurethane rubber, natural rubber, and chlorinated polyethylene. Or have been used.

  However, in the case of polyurethane rubber and chlorinated polyethylene, there is a problem that the friction coefficient decreases over time. In other words, there is a major drawback in that once hand grease or the like adheres to the roll surface, the coefficient of friction decreases and does not recover.

  On the other hand, in the case of natural rubber, the decrease in the coefficient of friction is small, but the deterioration due to ozone is large, and because of the influence of animal fats and oils such as hand oil, the clearance decreases due to swelling with time. In addition, there is a problem that the pressure at which the rolls come into contact with each other periodically needs to be adjusted, and furthermore, the swelling becomes remarkable and the function as a transport roll is lost.

  An endless belt for conveying paper sheets is made of a rubber material obtained by blending an ethylene-propylene-diene terpolymer and a highly saturated nitrile rubber, and has heat resistance, ozone resistance, and cold resistance for durability. Although improved ones have been proposed, there is no mention of the problem of a decrease in the coefficient of friction or swelling due to hand fat (see Patent Document 1).

JP-A-62-161650 (Claims)

  In view of such circumstances, an object of the present invention is to provide a transfer rubber roll that has a small decrease in friction coefficient with time, does not deteriorate with ozone, and has a small swelling due to hand oil.

  According to a first aspect of the present invention, which achieves the above object, there is provided a transport rubber roll for feeding and transporting an object to be transported manually, wherein an ethylene-propylene-diene-based copolymer and a nitrile-based rubber are provided. And a blending ratio of the ethylene-propylene-diene-based copolymer and the nitrile-based rubber of 2: 8 to 7: 3, which is caused by swelling in JIS # 3 oil. The rubber roll for conveyance is characterized in that the mass change rate is half or less of the mass change rate of each of the ethylene-propylene-diene copolymer and the nitrile rubber alone.

  According to a second aspect of the present invention, there is provided the transport rubber roll according to the first aspect, wherein a hydrogenated nitrile rubber in which zinc methacrylate is finely dispersed is compounded as a part of the nitrile rubber. is there.

  A third aspect of the present invention is the transfer rubber roll according to the first or second aspect, wherein a difference between an initial friction coefficient and a friction coefficient after transporting 4000 sheets is 0.2 or less.

  A fourth aspect of the present invention is the transfer rubber roll according to any one of the first to third aspects, wherein white rubber is contained as a filler.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a vinyl acetate copolymer is contained based on a total of 100 parts by weight of the ethylene-propylene-diene-based copolymer and the nitrile-based rubber. A rubber roll for conveyance characterized by being blended in an amount of 10 parts by weight or less.

  According to the present invention, the swelling property of various kinds of fats and oils is reduced by blending an ethylene-propylene-diene copolymer (EPDM) and a nitrile rubber (NBR, HNBR), and adhesion of hand fats and the like is achieved. It is based on the new finding that the reduction of the friction coefficient due to the oil is significantly reduced, and the swelling due to animal fats such as hand fat can be prevented.

  That is, EPDM generally swells easily in fats and oils, while nitrile rubber generally hardly swells in fats and oils, but there are also fats and oils that swell this. However, the present inventors have found that a blend of EPDM and a nitrile-based rubber is unlikely to swell even with oils and fats in which the nitrile-based rubber easily swells, for example, mineral oils such as JIS # 3 oil. Completed the invention. A blend of EPDM and a nitrile-based rubber has the same friction coefficient recovery as oil-fat adhesion as the nitrile-based rubber alone, and is more excellent in ozone resistance than the nitrile-based rubber alone.

  In the present invention, the ethylene-propylene-diene copolymer can be used as long as it is generally commercially available as an ethylene-propylene-diene copolymer (or EPDM). A commercially available product may be used.

  The nitrile rubber used in the present invention is not particularly limited as long as it is commercially available as nitrile rubber (NBR) or hydrogenated nitrile rubber (HNBR).

  Here, a hydrogenated nitrile rubber in which zinc methacrylate is finely dispersed (hereinafter, also referred to as zinc methacrylate-added HNBR) may be blended as a part of the nitrile rubber. By adding even a small amount of the zinc methacrylate-added HNBR to the nitrile rubber, the hardness and strength of the rubber can be significantly improved as compared with the case of using carbon or other fillers, and the other properties can be maintained. There is an advantage that there is. The blending amount of zinc methacrylate-added HNBR is not particularly limited, but in order to obtain a remarkable effect, it may be blended in an amount of about 20 to 80% by weight, preferably about 30 to 70% by weight of the nitrile rubber. As the zinc methacrylate-added HNBR, ZSC (trade name) manufactured by Zeon, which is a hydrogenated HNBR in which zinc methacrylate of 10% by weight or more is highly finely dispersed can be given.

  In the present invention, the blending ratio of the ethylene-propylene-diene-based copolymer and the nitrile-based rubber is 2: 8 to 7: 3, preferably 2: 8 to 5: 5. The range is not limited to this as long as the range can be obtained. Further, in order to enhance the compatibility between the two, the total weight of the ethylene-propylene-diene-based copolymer and the nitrile-based rubber is 100 parts by weight, and the vinyl acetate copolymer may be blended in an amount of 10 parts by weight or less. .

  The rubber roll for conveyance of the present invention is obtained by blending EPDM with a nitrile rubber, adding a vulcanizing agent and, if necessary, a filler (reinforcing agent), a plasticizer and various additives, and kneading the mixture. It was done.

  Note that carbon or white carbon may be used as the filler, but white carbon is preferably used in consideration of contamination of the transported object and maintenance of the coefficient of friction.

  As described above, the transfer rubber roll of the present invention has a reduced swelling property with respect to various fats and oils, and the friction coefficient recovers over time even if fats and oils adhere, and the friction coefficient is stable even after long-term use. In addition, it was found that there was an effect that ozone deterioration was small.

  Hereinafter, the present invention will be described in more detail.

(Example 1)
14 parts by weight of carbon and 14 parts by weight of silica (white carbon) were added to 100 parts by weight of a rubber material in which EPDM and HNBR were blended at a ratio of 4: 6, vulcanized and molded, and the surface was polished. A rubber roll for conveyance was manufactured. Rubber hardness (JIS A) was 60 °.

(Example 2)
A transport rubber roll of Example 2 was manufactured in the same manner as in Example 1 except that NBR was used instead of HNBR. Rubber hardness (JIS A) was 60 °.

(Example 3)
14 parts by weight of carbon was added to 100 parts by weight of a rubber material in which EPDM and HNBR were blended at a ratio of 4: 6, vulcanized and molded, and the surface was polished to produce a transfer rubber roll of Example 3. Rubber hardness (JIS A) was 70 °.

(Example 4)
Vulcanization and molding were carried out in the same manner as in Example 1, except that a mixture of normal HNBR and ZSC (trade name: Zeon), which is an HNBR with zinc methacrylate, mixed at a ratio of 5: 5 was used as the HNBR in Example 1. Then, the surface was polished to produce the transporting rubber roll of Example 4. Rubber hardness (JIS A) was 83 °.

(Comparative Example 1)
A transport rubber roll of Comparative Example 1 was manufactured in the same manner as in Example 1 except that HNBR was used as the rubber material. Rubber hardness (JIS A) was 70 °.

(Comparative Example 2)
A transport rubber roll of Comparative Example 2 was manufactured in the same manner as in Example 1 except that EPDM was used as the rubber material. Rubber hardness (JIS A) was 65 °.

(Comparative Example 3)
A transport rubber roll of Comparative Example 3 was manufactured in the same manner as in Example 1 except that polyurethane rubber was used as the rubber material. Rubber hardness (JIS A) was 60 °.

(Comparative Example 4)
A transport rubber roll of Comparative Example 4 was manufactured in the same manner as in Example 1 except that natural rubber was used as the rubber material. Rubber hardness (JIS A) was 70 °.

(Comparative Example 5)
A transfer rubber roll of Comparative Example 5 was manufactured in the same manner as in Example 1 except that chlorinated polyethylene was used as the rubber material. Rubber hardness (JIS A) was 60 °.

(Test Example 1)
According to JIS K6258, the transfer rubber rolls of the respective Examples and Comparative Examples were immersed in JIS # 3 oil, horse fat, and grease at 55 ° C. for 24 hours, and the weight after wiping off the grease on the surface was measured. It measured and compared the weight change rate. The results are shown in FIGS.

  As a result, the transport rubber rolls of Examples 1 to 4 have a small weight change rate for each of JIS # 3 oil, horse fat, and grease, and are significantly superior to the transport rubber rolls of Comparative Examples 1 to 4. I knew it was there. In Comparative Example 5, the rate of change in weight was relatively small, as in Examples 1 to 3. However, as shown in Test Example 2 described later, once fat adhered and the friction coefficient decreased, it did not recover. There is a problem.

(Test Example 2)
After immersion at 55 ° C. for 10 hours and 20 hours using oleic acid and palmitic acid, which are considered to be closer to human fats than JIS # 3 oil, horse fat, and grease, and then wiping off the fat on the surface Were measured and the rate of change in weight was compared. The results are shown in FIGS.

  As a result, no change in weight was observed in the transfer rubber rolls of Examples 1 to 4, but the transfer rubber rolls of Comparative Examples 1 to 4, especially Comparative Examples 2 and 4 were JIS # 3 oil, horse fat, and grease. Greater weight change.

(Test Example 3)
Horse fat was applied to the surfaces of the transfer rubber rolls of Examples 1, 3, 4 and Comparative Examples 1 to 5, and the friction coefficient was measured immediately after application and 10 minutes later, and compared with the friction coefficient before application. The result is shown in FIG.

  Here, as shown in FIG. 7, the coefficient of friction is such that each transport rubber roll 11 is pressed against a rotatable free roll 12 with a load of 300 gf across a paper 13 to rotate the transport rubber roll 11. The load Q (N) measured by the load cell 14 attached to one end of the paper 13 at the time of driving was determined and calculated by the following equation. The dimensions of the rubber elastic body of the transfer rubber roll were 16 mm in inner diameter × 24 mm in outer diameter × 24 mm in width, roll rotation speed (peripheral speed) 250 mm / sec, and paper type: Xerox-P (manufactured by Fuji Xerox Office Supply).

[Equation 1]
μ = Q (N) / (300 gf × 0.0098)

  As a result, it was found that the transfer rubber roll of Example 1 recovered to the same level as before the application after 10 minutes although the coefficient of friction immediately after the application decreased. This was the same effect as the transport rubber roll of Comparative Example 1 using only HNBR and the transport rubber roll of Comparative Example 4 using only natural rubber.

(Test Example 4)
The transfer rubber rolls of Example 1 and Comparative Examples 1 to 3 were mounted on an actual machine, and the friction coefficient after 16,000 sheets of PPC paper were tested was measured. The result is shown in FIG.

  As a result, in the transfer rubber roll of Example 1, the friction coefficient decreased only by 0.2 compared with the initial state after passing 16,000 sheets as well as after passing 4000 sheets. It was found that the coefficient of friction was more stable than that of the transfer rubber roll No. 3.

(Test Example 5)
An ozone deterioration test was performed on the transfer rubber rolls of Example 1 and Comparative Example 4 according to JIS K6259. Table 1 shows the results.

  As a result, in the transfer rubber roll of Comparative Example 4 using only natural rubber, the deterioration level was A-2 after 30 hours, and A-5 after 90 hours. However, the transfer rubber roll of Example 1 was 90 hours. It was found that it did not deteriorate after the lapse of time.

It is a figure showing the result of the swelling test of example 1 of the present invention. It is a figure showing the result of the swelling test of Test Example 1 of the present invention. It is a figure showing the result of the swelling test of Test Example 1 of the present invention. It is a figure showing the result of the swelling test of Test Example 2 of the present invention. It is a figure showing the result of the swelling test of Test Example 2 of the present invention. It is a figure showing change of a coefficient of friction of example 3 of the present invention. It is a figure showing a measuring method of a friction coefficient of the present invention. It is a figure which shows the result of the friction coefficient after the paper passing test of Test Example 4 of this invention.

Explanation of reference numerals

11 Rubber Roll for Conveyance 12 Free Roll 13 Paper 14 Load Cell

Claims (5)

In a transport rubber roll for feeding and transporting a transported object introduced by hand, an ethylene-propylene-diene-based copolymer and a rubber-like elastic body obtained by blending a nitrile-based rubber, The compounding ratio of the ethylene-propylene-diene copolymer and the nitrile rubber is 2: 8 to 7: 3, and the mass change rate due to swelling with respect to JIS # 3 oil is the ethylene-propylene-diene copolymer. And a rate of change in mass of only one of the above-mentioned nitrile-based rubber and half of the rate of change in mass of the rubber. The transfer rubber roll according to claim 1, wherein a hydrogenated nitrile rubber in which zinc methacrylate is finely dispersed is compounded as a part of the nitrile rubber. 3. The transporting rubber roll according to claim 1, wherein a difference between an initial friction coefficient and a friction coefficient after transporting 4000 sheets is 0.2 or less. The transporting rubber roll according to any one of claims 1 to 3, further comprising white carbon as a filler. In any one of claims 1 to 4, the vinyl acetate copolymer is compounded in an amount of 10 parts by weight or less based on 100 parts by weight of the ethylene-propylene-diene-based copolymer and the nitrile-based rubber in total. Characteristic transfer rubber roll.

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