JP5909328B2 - Backup rubber roll - Google Patents

Description

  The present invention relates to a rubber roll, and more particularly to a backup roll used together with a roll for a coater such as a film and a rubber roll for conveyance such as a sheet or paper. More specifically, the present invention relates to a backup roll installed in contact with a coater roll such as a film.

  Conventionally, in continuous coating of a strip-like substrate such as a film or sheet, a rubber roll for coating on a strip-like substrate called a coater roll, and a coater roll are installed in contact with the coater roll to convey the strip-like substrate. A backup role that is in use. In order to smoothly transport the belt-like substrate, the backup roll is required to have a slip surface on the roll surface.

The following rubber compositions are known for imparting slipperiness to the roll surface, but any of the rubber compositions has the following problems.
(1) There is a rubber composition in which an elastomer having an unsaturated bond in a basic skeleton such as acrylonitrile-butadiene-isoprene rubber (NBR) or chloroprene rubber (CR) is surface-treated. However, if a rubber roll using this rubber composition as a surface layer is continuously used, the slipperiness is lowered due to wear of the surface layer of the rubber roll. In addition, for example, there are cases where rolls are used in an ozone environment in film processing, and ozone degradation resistance has become a problem.

(2) There is a rubber composition in which spherical polyethylene or fluororesin that imparts slipperiness to an elastomer is mixed. However, since different types of substances are simply mixed in the rubber composition, the product may be removed by dropping off (contamination of the object to be treated (strip-shaped substrate) contacting the roll when the different types of mixture floats on the roll surface). There is an impact.
(3) There is a rubber roll in which a sliding property imparting agent is coated on the surface of a rubber roll using an elastomer such as ethylene-propylene-diene terpolymer (EPDM). However, the slippage of the rubber roll decreases with wear on the roll surface.

  On the other hand, the present inventor, as a candidate for a material used for the surface layer of the rubber roll, is a mixed liquid containing a polyolefin resin as a main component, a nonpolar wax having a melting point of 50 to 100 ° C., a vinyl monomer and a radical polymerization initiator. A thermoplastic resin composition containing a surface physical property improver for a resin molded article containing a polymer obtained by emulsion polymerization or suspension polymerization, wherein the vinyl monomer has a polarity different from that of a polyolefin resin (Patent Document) 1) was examined.

  However, when the composition described in Patent Document 1 is used, slipperiness is imparted to a thermoplastic resin having a high hardness, so that a low-hardness material is required for use as a rubber roll. In addition, there has been a demand for a rubber material having flexibility and slipperiness when coating the film. Furthermore, Patent Document 1 discloses that a thermoplastic elastomer is used. However, the thermoplastic elastomer has poor wear resistance, resilience, high temperature characteristics, and the like, and has been required to be modified.

  As a more specific problem, when a surface layer of a rubber roll is formed from the thermoplastic resin composition and this rubber roll is used as a backup roll that contacts a roll for a coater such as a film, the surface layer of the backup roll is It is conceivable that the wear reduces slipping property and is inferior in restorability, so that a dent due to pressing remains in the surface layer, or wrinkles or breakage occurs in a belt-like substrate such as a film during transportation.

JP 2009-167352 A

The present invention has been made in consideration of the above circumstances, and suppresses the reduction in slipperiness due to wear of the surface layer, and can avoid dents and creases in coating the surface layer. The purpose is to provide a backup roll.

The backup roll which concerns on this invention is a backup rubber roll arrange | positioned facing the roll for coaters of a film, and consists of a rubber roll. The backup rubber roll of the present invention comprises a cored bar and a surface layer made of a thermosetting elastomer composition provided on a peripheral surface of the cored bar, and the thermosetting elastomer composition is a thermoset elastomer. It is a cured product containing 10 to 50 parts by weight of a slip imparting agent with respect to 100 parts, the thermosetting elastomer is a polyolefin material, and the slip imparting agent includes a nonpolar wax having a melting point of 50 to 100 ° C. It is a granular radical polymer of a vinyl monomer .
The production method of a backup roll according to the present invention is a production method of a backup rubber roll disposed in contact with a roll for a coater of a film, and 100 parts of a thermosetting elastomer which is a polyolefin material, and 10 to 50 slip imparting agents. A step of forming a thermosetting elastomer composition obtained by mixing and crosslinking with a weight part as a surface layer on the peripheral surface of the cored bar. The slip imparting agent is a polymer obtained by emulsion polymerization or suspension polymerization of a mixed solution containing a nonpolar wax having a melting point of 50 to 100 ° C., a vinyl monomer, and a radical polymerization initiator.

According to the present invention, it is possible to provide a backup rubber roll that can suppress a reduction in slipperiness due to abrasion of the surface layer and can avoid wrinkles and breaks during coating of the surface layer and film.

Sectional drawing of the rubber roll which concerns on this invention. Explanatory drawing in the case of using the rubber roll which concerns on this invention as a backup roll for film processing.

Hereinafter, the rubber roll according to the present invention will be described.
In the present invention, the thermosetting elastomer composition for forming a slippery surface layer is obtained by first polymer-blending a slip imparting agent and a thermosetting elastomer and then crosslinking. Since the thermosetting elastomer composition is cross-linked by being cross-linked, it has a slip property evenly to the inside, so that the slip property can be maintained and dropping can be suppressed.

  Further, the thermosetting elastomer composition has the characteristics that the polymers are co-crosslinked by cross-linking, so that it is excellent in wear resistance, restorability, high temperature characteristics, and the like. Specifically, since the properties of the thermoplastic resin can be suppressed by co-crosslinking between the polymers, the wear resistance / restorability and the properties at high temperature are improved.

Therefore, according to the present invention, when a rubber roll provided with a surface layer made of the thermosetting elastomer composition on the peripheral surface of the cored bar is used as a backup roll in contact with a coater roll of a film, for example, There are improvements.
(Abrasion resistance)
According to the present invention, since the thermosetting elastomer composition is co-crosslinked, durability is improved. Therefore, a backup roll using the thermosetting elastomer composition is less likely to cause surface wear during use. On the other hand, since the thermoplastic elastomer composition does not cause co-crosslinking, surface abrasion may occur.

(Sustained slip)
According to the present invention, since the thermosetting elastomer and the slip imparting agent are polymer blended, the slip property is imparted uniformly not only on the outside (surface) but also on the inside (core metal side) of the rubber roll. Therefore, even if the surface is worn, the surface slipperiness is maintained.

(drop out)
According to the present invention, the thermosetting elastomer composition is not merely a mixture of different materials of the thermosetting elastomer and the slip imparting agent, but between the polymers of the thermosetting elastomer composition by co-crosslinking, and the molecules of the slip imparting agent. Since the polymer is bonded, dropping from the surface can be suppressed. However, since the thermoplastic elastomer composition is simply a mixture of different materials such as a thermoplastic elastomer and a slip imparting agent, it may fall off from the roll surface.

(Restorability)
According to the present invention, since the recoverability of the thermosetting elastomer composition is improved, no dent remains even when pressed from the coater roll when used as a backup roll. Moreover, since it is low hardness, it can suppress generating a wrinkle, a crease, etc. in strip | belt-shaped base materials, such as a film. On the other hand, since the thermoplastic elastomer composition has a low rubber elastic modulus, it is inferior in restorability, and when pressed from the coater roll, a dent remains. Furthermore, since the thermoplastic elastomer has a high hardness, when used as a backup roll, it may cause wrinkles or breaks in the film that is a belt-like substrate during transportation, which is not suitable as a material for the backup roll. is there.

(High temperature characteristics)
In general, a backup roll changes its shape because the inside of the roll generates heat by receiving a load at a portion in contact with the coater roll of the film. According to the present invention, since the thermosetting elastomer has heat resistance, it can be used even in a high temperature environment. However, when the thermoplastic elastomer composition is used on the roll surface, it is considered that the thermoplastic elastomer is susceptible to heat, and thus is easily deformed due to an applied load.

  In the present invention, the thermosetting elastomer composition preferably includes 10 to 50 parts by weight of a slip imparting agent with respect to 100 parts of the thermosetting elastomer. The reason for this is that if the slip imparting agent is less than 10 parts by weight, a sufficient friction coefficient reducing effect cannot be exhibited when the composition is applied to a rubber roll. If the slip imparting agent exceeds 50 parts by weight, compression set This is because the numerical value deteriorates and cannot be used as a rubber roll.

  The thermosetting elastomer is a polyolefin material such as natural rubber, styrene butadiene rubber, isoprene rubber, acrylonitrile-butadiene rubber, butyl rubber, chloroprene rubber, epichlorohydrin rubber, fluorine rubber, ethylene propylene rubber (EPDM), acrylic. Examples thereof include rubber, silicone rubber, urethane rubber, and chlorosulfonated polyethylene (CSM).

  The slip imparting agent means a polymer obtained by emulsion polymerization or suspension polymerization of a mixed solution containing a nonpolar wax having a melting point of 50 to 100 ° C., a vinyl monomer and a radical polymerization initiator. Examples of the slipping agent include NOF ALLOY KA832 manufactured by NOF Corporation.

Next, specific examples and comparative examples of the present invention will be described.
(Example 1)
First, 100 parts of EPDM as a thermosetting elastomer and 20 parts by weight of a polymer (trade name: NOFALOY KA832 manufactured by NOF Corporation) as a slip imparting agent and 5 weights of peroxide (peroxide) as a vulcanizing agent After adding a part and mixing, it crosslinks and obtains a thermosetting elastomer composition. This thermosetting elastomer composition is excellent in wear resistance, resilience, high temperature characteristics and the like because the polymers are co-crosslinked by crosslinking.

Subsequently, as shown in FIG. 1, the surface layer 1 made of this rubber composition is molded on the surface of the core metal 2 to obtain a cylindrical body, and then the surface of the cylindrical body is polished to obtain a diameter of the core metal 2: A rubber roll 3 having an outer diameter of 30 mm, an outer diameter of the surface layer 1 of 50 mm, and a length of 100 mm is obtained.
A conventional method was used for polishing the cylindrical body. That is, the cylindrical body was installed in a grinder equipped with a grindstone, and the grinder was driven to rotate the cylindrical body and the grindstone of the grinder, thereby polishing the surface of the cylindrical body in contact with the grindstone.

According to Example 1, a rubber roll having a friction coefficient of 0.61 to 0.65 was obtained. In addition, it has confirmed that the friction coefficient of this rubber roll did not change before and behind grinding | polishing.
The friction coefficient is measured using a friction coefficient measuring instrument (trade name: HEIDON Tribogear Muse TYPE: 94i) manufactured by Shinto Kagaku Co., Ltd., and the coefficient of friction (μs) between the PET film and the rubber roll is measured. It was.

  The rubber roll according to Example 1 can be used as a backup roll 13 disposed in contact with a coater roll 12 that coats a film 11, for example, as shown in FIG. According to such a rubber roll, since the surface is slippery and has a low hardness, the film 11 can be transported without causing wrinkles or creases, so the film 11 can be smoothly coated with the coater roll 12. Can be processed.

(Example 2)
In Example 2, a rubber roll was obtained in the same manner as in Example 1 except that 50 parts by weight of a polymer (trade name: NOFALLOY KA832 manufactured by NOF Corporation) as a slip imparting agent was added. It was.
According to Example 2, rubber rolls having a friction coefficient of 0.41 to 0.45 were obtained. In addition, it was confirmed that the friction coefficient of this rubber roll was not changed before and after polishing, and the same effect as in Example 1 was obtained.

(Comparative Example 1)
In Comparative Example 1, as compared with Example 1, a cored bar was made in the same manner as in Example 1 except that the polymer as a slip imparting agent was not added and that the surface layer was coated with a slidability imparting agent by spraying after polishing. A rubber roll having a diameter of 120 mm, an outer diameter of the surface layer of 140 mm, and a length of 1400 mm was obtained. The spraying was performed from a location about 300 mm away from the roll. This spraying is performed in order to ensure the release property and slipperiness between the film and the rubber roll.

  According to Comparative Example 1, the friction coefficient of the rubber roll after polishing was 1.50 or more. The coefficient of friction after spraying was 0.60 to 0.70. Furthermore, when the rubber roll according to Comparative Example 1 is used as a backup roll for film coating processing, the surface layer is worn and the surface slipping property is poor, and the film is wrinkled in a short period of time. It was.

(Comparative Example 2)
In Comparative Example 2, the diameter of the core metal: 30 mm, the outer diameter of the surface layer: 50 mm, and the length of 100 mm are the same as in Example 1 except that the polymer as a slip imparting agent is not added. A rubber roll was obtained. According to Comparative Example 2, a rubber roll having a friction coefficient of 1.50 or more was obtained. Moreover, when the rubber roll which concerns on the comparative example 2 was used as a backup roll for the coating process of a film, a film did not slip and a wrinkle entered into the film and it was not able to be used.

(Comparative Example 3)
In Comparative Example 3, as compared with Example 1, a rubber roll was obtained in the same manner as in Example 1 except that 60 parts by weight of a polymer as a slip imparting agent (trade name: NOFALLOY KA832 manufactured by NOF Corporation) was added. It was.
According to Comparative Example 3, a rubber roll having a friction coefficient of 0.40 to 0.45 was obtained. In addition, when the rubber roll according to Comparative Example 3 was used as a backup roll for film processing, after pressing the backup roll against the roll for the coater, the backup roll was not restored, and a dent remained by simply pressing with a nail before use, It could not be used as a roll requiring surface smoothness.

(Comparative Example 4)
In Comparative Example 4, a rubber roll was obtained in the same manner as in Example 1 except that 5 parts by weight of the slipperiness imparting agent polymer was added. As a result, a rubber roll having a friction coefficient of 1.50 or more was obtained.

The following can be considered when Examples 1 and 2 and Comparative Examples 1 to 4 are summarized.
(1) As a result of adding a polymer having a slipperiness imparting agent to Examples 1 and 2 within a range of 10 to 50 parts by weight, the numerical values of the friction coefficients of the rubber rolls of Examples 1 and 2 are low, and slipperiness is low. I know that there is. Further, in Example 2, since the numerical value of the friction coefficient is low even when the surface is polished, the thermosetting elastomer polymer and the thermosetting elastomer polymer and the slip imparting agent molecules are bonded by co-crosslinking. Therefore, it can be seen that the slipperiness is maintained even when the roll surface is worn.

(2) In contrast to Examples 1 and 2, in Comparative Examples 3 and 4, a polymer having a slipperiness-imparting agent was added outside the range of 10 to 50 parts by weight. As a result, slipperiness was obtained in Comparative Example 3, but unlike Example 2, the roll did not recover because the numerical value of compression set of the thermosetting elastomer composition was poor.
(3) In contrast to Examples 1 and 2, in Comparative Example 1, instead of adding a polymer, spraying was performed to impart slipperiness to the surface. However, the surface slipperiness of the rubber roll of Comparative Example 1 was lost over time. On the other hand, it was found from Example 2 that the slipperiness was maintained even when the surface was worn.
(4) Since Comparative Example 2 did not add any slipperiness, a high numerical friction coefficient was obtained. From this, it was found that the slipperiness of this roll was very low compared to the Examples.

  Next, the difference between the thermosetting elastomer and the thermoplastic elastomer according to the present invention will be described. Note that the slip imparting agent (trade name: NOFALOY KA832 manufactured by NOF Corporation) may cause the slip component to vaporize in an environment exceeding 200 ° C. In order to avoid this vaporization, it is necessary to process the thermosetting and thermoplastic elastomers at 200 ° C. or lower.

(Reference Example 1)
First, 100 parts of EPDM was prepared as a thermosetting elastomer. As thermoplastic elastomers, ExxonMobil's product name: Santoprene 201-73 with a melting point of 202 ° C and Mitsui Chemicals' product name: Miralastomer 7030NS with a melting point of 160 ° C were prepared. Next, as shown in Table 1 below, each elastomer is added with a nophalloy (slip imparting agent), each processed in the vicinity of the melting point, and various physical property values (tensile strength, (Elongation, tear strength, impact resilience, compression set, friction coefficient). Specifically, in thermosetting elastomer, 10, 20, 30, 40, and 50 parts of NOF alloy are added to 100 parts of EPDM, respectively, and in thermoplastic elastomer, 100 parts of Santoprene 201-73 and 30 parts of NOF alloy are added to 100 parts of Miralastomer 7030NS. Part was added. For measuring the compression set, the compression set after each elastomer before and after processing was compressed at a temperature of 100 ° C. for 25 hours by 25% was measured. Moreover, the friction coefficient was measured using a HEIDON friction coefficient measuring instrument, and the friction coefficient between each elastomer and the PET film before and after processing was measured.

  From Table 1, the following could be confirmed. First, EPDM (thermosetting elastomer) exhibited an effect of reducing the friction coefficient when a slipping agent was added without applying a temperature higher than 200 ° C. during processing. In contrast, Santoprene 201-73, which is a thermoplastic elastomer, must be processed at a temperature higher than 200 ° C. in order to add the slip imparting agent, and even if the slip imparting agent is added and processed, the friction is caused. No reduction in coefficient was observed. This is considered that the slip imparting agent was vaporized at a processing temperature of more than 200 ° C.

  Next, EPDM maintained its hardness regardless of the addition amount of the slip imparting agent, whereas the thermoplastic elastomer was confirmed to decrease in hardness due to an increase in the addition amount of the slip imparting agent. From the result of Miralastomer 7030NS, which is a thermoplastic elastomer that does not require a processing temperature for adding a slipping agent to exceed 200 ° C., it was confirmed that the change in hardness was not related to the processing temperature.

  In addition, it was confirmed that the thermosetting elastomer was superior to the thermoplastic elastomer in terms of tensile strength, elongation, tear strength, and impact resilience.

(Reference Example 2)
First, as in Reference Example 1, 100 parts of EPDM was prepared as a thermosetting elastomer. Moreover, 100 parts of Miralastomer 7030NS was prepared as a thermoplastic elastomer. Subsequently, as shown in Table 2 below, 10, 30, and 50 parts of NOF alloy are added to 100 parts of EPDM for thermosetting elastomer, and 10, 30, and 50 parts of NOF alloy are added to 100 parts of Miralastomer 7030NS for thermoplastic elastomer, respectively. And processed. Physical property values (change in tensile strength, change in elongation, change in tear strength) of each elastomer before and after processing at high temperature (120 ° C.) were measured.

  From Table 2, the following could be confirmed. First, it was remarkably confirmed that the thermoplastic elastomer had a lower hardness and a higher physical property value than the thermosetting elastomer. This decrease in hardness and physical property values showed a further decreasing tendency as the amount of the slip-imparting agent added increased.

  Also, in compression set (see Table 1 above), the value of the thermoplastic elastomer was higher than that of the thermosetting elastomer under high temperature conditions (100 ° C.). This means that a compression set is generated in a thermoplastic elastomer rather than a thermosetting elastomer.

  For these reasons, in the provision of a roll used in a high temperature environment such as coating processing on a film, a roll using a thermosetting elastomer having excellent physical property values at a high temperature is desirable.

  In the present invention, the blending ratio of the slip imparting agent is not limited to that described above, and may be 10 to 50 parts by weight. In addition to slip imparting agents and peroxides, known compounding agents such as vulcanizing agents, vulcanization aids, vulcanization accelerators, anti-aging agents, plasticizers and fillers may be used as necessary. it can. Furthermore, the thermosetting elastomer is not limited to EPDM, and other polyolefin-based materials may be used.

  Further, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Surface layer, 2 ... Core metal, 3 ... Rubber roll, 11 ... Film, 12 ... Coater roll, 13 ... Backup roll.

Claims (2)

A backup rubber roll placed in contact with the film coater roll,
Comprising a metal core and a surface layer composed of the thermosetting elastomer composition is provided on the peripheral surface of the core metal,
The thermosetting elastomer composition is a cured product containing 10 to 50 parts by weight of a slip imparting agent with respect to 100 parts of the thermosetting elastomer ,
The thermosetting elastomer is a polyolefin-based material,
The backup rubber roll , wherein the slip-imparting agent is a granular radical polymer of a vinyl monomer containing a nonpolar wax having a melting point of 50 to 100 ° C.   A method for producing a backup rubber roll disposed in contact with a film coater roll,
  A thermosetting elastomer composition obtained by mixing 100 parts by weight of a thermosetting elastomer which is a polyolefin-based material and 10 to 50 parts by weight of a slip imparting agent and crosslinking is formed as a surface layer on the peripheral surface of the cored bar. With a process,
  The slip imparting agent is a polymer obtained by emulsion polymerization or suspension polymerization of a mixed solution containing a nonpolar wax having a melting point of 50 to 100 ° C., a vinyl monomer and a radical polymerization initiator. A method for producing a backup rubber roll.

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