JP2008296234A - Sealing device for roll neck journal box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device for a roll neck journal box, which sealing device does not require the supply of lubricant to a seal from outside, and has a self-lubricating property. <P>SOLUTION: The sealing device 1 for the roll neck journal box comprises a plurality of seals 8, 9, 10 which are arranged between a fillet ring 3 fixed to the outer periphery of the neck 2a of a roll and a bearing cover 7 provided so as to be connected to the journal box 6 of a bearing device 4 for rotatably supporting the end portion 2b of the roll, and are brought into sliding contact with the outer periphery of the fillet ring 3 on the inside diameter side thereof, and are fixed to the bearing cover 7 on the outside diameter side thereof. Foam solid lubricant 11, which contains lubricating components and resinoid components as indispensable components, and is a solid having the porous resinoid components by foaming and hardening the resinoid components, is enclosed in the space surrounded by the fillet ring 3, the bearing cover 7, and seals 8, 9, 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sealing device for a roll neck axle box. For example, in a bearing that rotatably supports an axial end of a roll for rolling a metal material, the axial opening end is sealed to allow water to enter an internal space. The present invention relates to a sealing device for a roll neck axle box that can prevent intrusion.

Rolling bearings used in harsh environments that come in contact with a large amount of water generally employ highly sealable oil seals in the seal structure of the sealing device, but the lip portion of the oil seal slides against the mating member. Since it hardens due to frictional heat and gradually wears out, it is inevitable that the sealing performance deteriorates during use. When the lubricant is not supplied in the vicinity of the oil seal lip, wear of the oil seal lip portion is promoted, and an early deterioration of the sealing performance occurs.
For example, a roll neck having a structure for the purpose of preventing intrusion of rolling water and eliminating leakage of lubricating oil to the roll body side is known (see Patent Document 1), but seals attached in double rows (see FIG. In the middle 8, 14), the grease easily flows to either one of the seals.
The seal with less grease flow does not supply sufficient lubricant to the lip, and the seal lip wears and cures due to frictional heat, which accelerates the sealing function and shortens the seal life. Connected.

  Further, a passage for supplying the lubricant is formed inside the bearing cover so that the lubricant is always supplied to the space region between the adjacent oil seals, and a lubricant replenisher is attached to the opening of the passage to seal the lubricant. A rolling mill roll neck sealing device that solves the shortage of lubricant supply to the lip is known (see Patent Document 2). However, there is a problem that the apparatus becomes complicated and that it takes time and effort to replenish the lubricant periodically and insufficient lubrication occurs when the timing of replenishment of the lubricant is shifted.

Further, a rolling mill roll neck sealing device is known in which a lubricating supply member is disposed between seal lips for the purpose of supplying lubricating oil to the seal lip (see Patent Document 3). However, in order to supply the lubricating oil, it is necessary for the lubricating supply member to reach a predetermined temperature, and frictional heat generated by sliding with the roll is transmitted to the solid lubricating member through the seal, and the solid lubricating member is heated. Therefore, there is a problem that the supply of the lubricating oil becomes unstable due to a change in the seal structure and a change in the amount of generated frictional heat due to the rotation speed of the roll.
Japanese Utility Model Publication No. 5-70705 JP 9-49572 A Japanese Patent Laid-Open No. 2005-180573

  The present invention has been made to address such problems, and an object of the present invention is to provide a sealing device for a roll neck shaft box having self-lubricating properties that eliminates the need for externally supplying a lubricant for the seal. .

  The roll neck shaft box sealing device according to the present invention is provided between a fillet ring fixed to the outer periphery of the roll neck and a bearing cover provided in connection with the shaft box of the bearing device that rotatably supports the roll neck. A roll neck shaft box sealing device comprising a double row seal in which the inner diameter side is in sliding contact with the outer periphery of the fillet ring and the outer diameter side is fixed to the bearing cover, the fillet ring, the bearing cover, A solid foamed lubricant obtained by foaming and curing a mixture containing a lubricating component, a resin component, a curing agent, and a foaming agent is enclosed in a space surrounded by the seal.

Among the solid foam lubricants, the first solid foam lubricant is at least one lubricating component whose lubricating component is selected from hydrocarbon-based lubricants and hydrocarbon-based greases, and the resin component is a polymer main component. The chain is composed of hydrocarbons, and is a liquid rubber having a hydroxyl group in an amount such that the hydroxyl value is 25 mg KOH / g to 110 mg KOH / g at the end of the main chain, and the curing agent has an isocyanate group in the molecule It is an organic compound, the foaming agent is water, and the ratio of the liquid rubber and the curing agent is such that the hydroxyl group contained in the liquid rubber and the isocyanate group contained in the curing agent are equivalent (OH / NCO ) = 1 / (1.0 to 2.0), and the mixture contains 40 wt% to 80 wt% of the lubricating component and 5 wt% to 45 wt% of the liquid rubber based on the entire mixture. Features.
Further, the liquid rubber is a hydroxyl group-terminated diene polymer having a number average molecular weight of 1000 to 3500 having a hydroxyl group at the main chain terminal of a butadiene or isoprene polymer, or a modified hydroxyl group-terminated diene system obtained by hydrogenating the diene polymer. It is a polymer.
The organic compound having an isocyanate group in the molecule is a prepolymer having two or more isocyanate groups in the molecule and a ratio of the isocyanate group of 2.5 NCO% to 5.0 NCO%, or aromatic. It is a polyisocyanate.

Of the foamed solid lubricant, the second foamed solid lubricant is such that the lubricating component is at least one lubricating component selected from a hydrocarbon-based lubricant and a hydrocarbon-based grease, and the resin component is an isocyanate group It is a urethane prepolymer having a content of 2% by weight or more and less than 6% by weight, the foaming agent is water, and the mixture contains 30% to 70% by weight of the lubricating component with respect to the whole mixture. It is characterized by the subsequent open cell ratio being 50% or more.
The urethane prepolymer is at least one urethane prepolymer selected from an ester urethane prepolymer, a caprolactone urethane prepolymer, and an ether urethane prepolymer.
Further, the ratio of the isocyanate group to the functional group of the curing agent that reacts with the isocyanate group is an equivalent ratio (functional group of the curing agent / NCO) = 1 / (1.1 to 2.5). And
The ratio of the hydroxyl group of water to the functional group of the curing agent is an equivalent ratio (hydroxyl group of water / functional group of the curing agent) = 1 / (0.7 to 2.0).
The curing agent is an aromatic polyamino compound, particularly an aromatic polyamino compound having a substituent at a position adjacent to an amino group.

  The roll neck shaft box sealing device of the present invention includes a fillet ring fixed to the outer periphery of the roll neck, a bearing cover connected to the shaft box of the bearing device that rotatably supports the roll neck, and a seal. The enclosed space contains the lubrication component and resin component as essential components, and the foamed solid lubricant, which is a solid material obtained by foaming and curing the resin component, is enclosed. The lubricant is gradually released from the deformed foamed solid lubricant, and the lubrication performance of the sliding contact portion of the seal lip can be improved. Further, since this foamed solid lubricant can be flexibly deformed, it is possible to exert a positive effect of supplying the lubricant to the seal lip portion. For this reason, it is possible to prevent bearing damage due to poor lubrication resulting from water intrusion, and to improve bearing life.

  This foamed solid lubricant is a solid material in which a lubricating component and a resin component are essential components, the resin component is foamed and cured to be porous, and the lubricating component is occluded in the foamed and cured solid component. . For this reason, in the sealing device for roll neck axle box of the present invention, the retained amount of the lubricating component in the foamed solid lubricant enclosed in the sealing device is large, and the sliding contact surface is lubricated from the foamed solid lubricant during operation. Since the oil is gradually released, the lubrication performance of the seal lip sliding portion is excellent over a long period of time. In the present invention, “occlusion” means that a liquid / semi-solid lubricating component does not react with other compounding components and is contained in a solid resin without becoming a compound.

  The roll neck axle box sealing device of the present invention will be described with reference to the drawings. FIG. 2 is a diagram showing a configuration around a roll neck of a rolling mill installed in an ironworks. As shown in FIG. 2, the shaft end 2 b of the roll 2 of the rolling mill is supported by a roll fixing jig (not shown) via the bearing devices 4 and 5 and the shaft box 6. The roll neck 2a is sandwiched between the roll 2 and the shaft end 2b, and the sealing device 1 is provided on the outer periphery of the roll neck 2b so that rolling water or the like does not enter the bearing devices 4 and 5 side.

  FIG. 1 is a sectional view showing an embodiment of a sealing device for a roll neck axle box according to the present invention. As shown in FIG. 1, a roll neck shaft box sealing device 1 includes a fillet ring 3 fixed to the outer periphery of a roll neck 2a of a rolling mill and a shaft of a bearing device 4 that rotatably supports a shaft end 2b of the rolling mill. 3 rows of seals 8, 9, 10 that are assembled between the bearing cover 7 connected to the box 6, the inner diameter side is in sliding contact with the outer periphery of the fillet ring 3, and the outer diameter side is fixed to the bearing cover 7. In the space surrounded by the fillet ring 3, the bearing cover 7, and the seals 8, 9, and 10, the lubricating component and the resin component are essential components, and the resin component is foamed and cured to make it porous. The foamed solid lubricant 11 which is a solid material is enclosed.

  Taking this seal 8 as an example, a metal ring 8b is embedded in the base end portion, and the base end portion is reinforced by the metal ring 8b. Further, the seal lip portion 8a is made of nitrile rubber (for example, NBR). By disposing the nitrile rubber on the outer periphery of the metal ring 8b at the base end portion, the seal lip portion 8a is fitted at the fitting portion with the inner peripheral surface of the bearing cover 7. The seal is secured. Even if the outer peripheral surface of the fillet ring 3 is worn or decentered, the seal lip portion 8a needs to be surely followed. Therefore, a spring 12 is attached to the outer periphery of the sliding contact portion of the seal lip portion 8a. The seal lip portion 8a is pressurized toward the outer peripheral surface side of the fillet ring 3 by the elastic force of 12. This configuration is the same for the seals 9 and 10. Since the lubricating component occluded in the encapsulated foamed solid lubricant 11 is gradually released to the sliding contact surface between each seal lip portion and the outer peripheral surface of the fillet ring 3 during operation, Lubricity can be maintained. The sealing device 1 also serves to prevent the grease filled in the bearing device 4 from flowing out.

The foamed solid lubricant used in the present invention occludes the lubricating component in the resin, so that the resin is exuded by the external force such as centrifugal force and bending applied during operation or capillary action due to the flexibility of the resin. Slow release from between molecules to the outside. At this time, the amount of the lubricating oil or the like that oozes out can be minimized by changing the degree of elastic deformation according to the magnitude of the external force or the like by selecting the resin. Further, the density of the foamed solid lubricant can be changed by controlling the blending amount of the blending components of the mixture.
Further, in the foamed solid lubricant used in the present invention, the resin component has a large surface area due to foaming, and the excess lubricating oil or the like that has oozed out can be temporarily retained in the foam bubbles again. The amount of lubricating oil or the like to be discharged is stable, and the amount of lubricating oil or the like retained is larger than that in a non-foamed state by occluding the lubricant in the resin and impregnating the bubbles.
In addition, the energy required for bending is very small compared to a non-foamed body, and flexible deformation is possible while maintaining the lubricating component at a high density.

As the resin component constituting the foamed solid lubricant used in the present invention, a resin component having rubber-like elasticity after foaming and curing, and having a leaching property of the lubricant component by deformation is preferable.
Foaming / curing may be in a form in which foaming / curing is performed at the time of resin production, or in a form in which a foaming agent is added to the resin component and foaming / curing is performed in molding. Here, curing means a cross-linking reaction and / or a phenomenon in which a liquid is solidified. The rubber-like elasticity means rubber elasticity and means that deformation applied by an external force returns to the original shape by eliminating the external force.

For the resin component of the foamed solid lubricant used in the present invention, it is preferable to use a urethane resin that is excellent in heat resistance and flexibility and can be reduced in cost. As the resin component, a first foamed solid lubricant using a liquid rubber having a hydroxyl group in the molecule described below and a second foamed solid lubricant using a urethane prepolymer containing a predetermined NCO are preferable.
Moreover, the resin component obtained by making the polyether polyol and polyisocyanate as a polyol react can be used.

As the resin component used in the first foamed solid lubricant that can be used in the present invention, it is preferable to use a urethane resin that is excellent in heat resistance and flexibility and can be reduced in cost. The hydroxyl group-containing component that forms the urethane resin is preferably a liquid rubber having a hydroxyl group in the molecule. This liquid rubber has a polymer main chain composed of hydrocarbons, and a hydroxyl value of 25 to 110 mg KOH at the end of the main chain. A liquid rubber having a hydroxyl group in an amount of / g 2 is preferable. When the hydroxyl value is less than 25 mg KOH / g, foaming / curing is not sufficient, and when the hydroxyl value exceeds 110 mg KOH / g, the elasticity of the foamed solid lubricant may be lost.
This liquid rubber is a hydroxyl group-terminated diene polymer having a number average molecular weight of 1000 to 3,500 having a hydroxyl group at the main chain terminal of a butadiene or isoprene polymer, or a modified hydroxyl group-terminated diene polymer obtained by hydrogenating the diene polymer. Coalescence can be used.
Examples of the hydroxyl-terminated liquid polybutadiene include poly-bd R45HT (manufactured by Idemitsu Kosan Co., Ltd.), poly-bd R15HT (manufactured by Idemitsu Kosan Co., Ltd.), NISSO-PB G-1000, G-2000, and G-3000 (manufactured by Nippon Soda Co., Ltd.). Examples of the hydroxyl group-terminated liquid polyisoprene include poly-ip (manufactured by Idemitsu Kosan Co., Ltd.), and examples of the hydrogenated hydroxyl group-terminated polydiene compound include Epol (manufactured by Idemitsu Kosan Co., Ltd.), NISSO-PB GI-1000, GI-2000, GI-3000 (made by Nippon Soda Co., Ltd.), etc. are mentioned.

  Further, the hydroxyl group-terminated polydiene compound or the hydroxyl group-terminated polydiene compound obtained by partially modifying the terminal hydroxyl group of the hydroxyl-terminated polydiene compound or the hydrogenated hydroxyl-terminated polydiene compound with an isocyanate group or an epoxy group or the hydrogenated hydroxyl-terminated polydiene compound is also included at the terminal. If it can be used. Two or more of these compounds may be mixed and used for the purpose of controlling the physical properties of the produced foam.

  The hydroxyl group-terminated polydiene polymer or the hydrogenated hydroxyl group-terminated polydiene polymer has a molecular structure similar to that of a lubricating component composed of paraffinic or naphthenic mineral oil composed of hydrocarbons, which will be described later. It is considered that the hydroxyl group-terminated polydiene polymer or the hydrogenated hydroxyl group-terminated polydiene polymer and the lubricating component molecule are intertwined by a relatively weak interaction. Therefore, many lubricating components can be impregnated in the molecule of the hydroxyl-terminated polydiene polymer or the hydrogenated hydroxyl-terminated polydiene polymer, and high lubricating component retention can be exhibited. By applying a strong force such as heat or centrifugal force to this, the interaction between the hydroxyl-terminated polydiene polymer or the hydrogenated hydroxyl-terminated polydiene polymer and the lubricating component is broken, and the lubricating component can be released gradually. it can.

The organic compound having an isocyanate group in the molecule as a curing agent for curing the liquid rubber can be used without particular limitation as long as it is an isocyanate compound that reacts with a hydroxyl group in the liquid rubber to extend the molecular chain or crosslink. Preferred isocyanate compounds include polyisocyanates. Polyisocyanates are particularly preferable because they can react with water to be a foaming agent described later to generate gas.
Examples of the polyisocyanates include polyisocyanates and / or prepolymers having two or more isocyanate groups in the molecule.

Polyisocyanates can include aromatic, aliphatic, or alicyclic polyisocyanates.
Aromatic polyisocyanates include tolylene diisocyanate (hereinafter referred to as TDI), diphenylmethane diisocyanate (hereinafter referred to as MDI), TDI multimer, MDI multimer, naphthalene diisocyanate (NDI), phenylene diisocyanate, diphenylene. Diisocyanate etc. are mentioned.
Examples of the aliphatic polyisocyanates include octadecamethylene diisocyanate, decamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and xylylene diisocyanate.
Examples of the alicyclic polyisocyanates include isophorone diisocyanate and dicyclohexylmethane diisocyanate.
Also, an adduct of the polyisocyanate and a polyol such as trimethylolpropane can be used.
When the reaction with the hydroxyl group that is the terminal functional group of the liquid rubber is performed at a high temperature, a blocked isocyanate in which an isocyanate group is blocked with a blocking agent such as phenols, lactams, alcohols, and oximes can be used. .

  In the case of reacting with a hydroxyl group-terminated polydiene polymer, aromatic polyisocyanates are preferred among the polyisocyanates, and TDI having excellent foamability and reactivity with the hydroxyl group-terminated polydiene polymer is preferred.

As the prepolymer having two or more isocyanate groups in the molecule, any prepolymer having an isocyanate group ratio of 2.5 to 5.0 NCO% can be used. In addition, NCO% is the weight% as an NCO group in a prepolymer. A 2.5 to 5.0 NCO% prepolymer can react with a hydroxyl group-terminated polydiene polymer or the like to obtain a urethane having high elasticity.
Prepolymers are classified into PPG type, PTMG type, ester type, caprolactone type, etc., depending on the type of monomer to be polymerized. There are Takenate L-1170 (manufactured by Mitsui Chemicals Polyurethane) and P-1158 (manufactured by Mitsui Chemicals Polyurethanes) in the PPG system, and Coronate 4090 (manufactured by Nippon Polyurethanes) in the PTMG system. Coronate 4047 (manufactured by Nippon Polyurethane Co., Ltd.) is used as the ester system, and Takenate L-1350 (manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.), Takenate L-1680 (manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.), and Sianaprene 7-QM are used as caprolactones. (Mitsui Chemical Polyurethane Co., Ltd.), Plaxel EP1130 (Daicel Chemical Industries Co., Ltd.) and the like.
Two or more kinds of the prepolymers can be mixed and used according to the purpose.

  The blending ratio of the hydroxyl group-terminated polydiene polymer having a terminal hydroxyl group or the hydrogenated hydroxyl group-terminated polydiene polymer and the isocyanate compound having an isocyanate group is equivalent ratio of hydroxyl group (—OH) to isocyanate group (—NCO). The range of (OH / NCO) = 1 / (1.0 to 2.0) is preferable, and the range of (OH / NCO) = 1 / (1.1 to 1.9) is preferable in consideration of particularly excellent foamability and elasticity. When (OH / NCO) is less than 1 / 2.0, the isocyanate group becomes excessive, the crosslink density is large, and the elasticity may be poor. On the other hand, when (OH / NCO) is greater than 1 / 1.0, the isocyanate group to be cross-linked is insufficient and curing is not sufficient.

The lubricating component that can be used for the first foamed solid lubricant can be used as long as it does not dissolve the solid component that forms the foam. Examples of the lubricating component include hydrocarbon-based lubricants, hydrocarbon-based greases, and mixtures of hydrocarbon-based lubricants and hydrocarbon-based greases.
Examples of the hydrocarbon-based lubricating oil include paraffinic and naphthenic mineral oils, hydrocarbon-based synthetic oils, GTL base oils, and the like. These can be used alone or as a mixed oil.
The hydrocarbon-based grease is a grease having a hydrocarbon oil as a base oil, and examples of the base oil include the above-described hydrocarbon-based lubricating oil. Examples of the thickener include lithium soaps, lithium complex soaps, calcium soaps, calcium complex soaps, aluminum soaps, aluminum complex soaps, and other urea compounds such as diurea compounds and polyurea compounds. It is not a thing. The diurea compound is obtained by the reaction of diisocyanate and monoamine, and the polyurea compound is obtained by the reaction of diisocyanate and polyamine.

  As the lubricating component, hydrocarbon synthetic wax, polyethylene wax, higher fatty acid ester wax, higher fatty acid amide wax, ketone / amines, hydrogenated oil, and the like can be mixed and used.

  Since the means for foaming the first foamed solid lubricant uses an isocyanate compound as a raw material, it is preferable to use water that reacts with the isocyanate compound to generate carbon dioxide gas.

The first solid foam lubricant is obtained by foaming and curing a mixture containing the above-described lubricating component, liquid rubber, a curing agent, and a foaming agent.
The blending ratio of the lubricating component is 40 to 80% by weight based on the entire mixture. If the lubricating component is less than 40% by weight, the supply amount of lubricating oil and the like is so small that it cannot function as a foamed solid lubricant, and if it exceeds 80% by weight, it will not solidify.
The blending ratio of the liquid rubber is 5 to 45% by weight, preferably 9 to 42% by weight, based on the entire mixture. When it is less than 5% by weight, it does not solidify, so it does not have a function as a foamed solid lubricant. When it is more than 45% by weight, the supply of the lubricant is small and it does not function as a foamed solid lubricant.

  In the first foamed solid lubricant, the expansion ratio is preferably 1.1 to 50 times, more preferably 1.1 to 10 times. When the expansion ratio is less than 1.1 times, the bubble volume is small and deformation cannot be allowed when external stress is applied. If it exceeds 50 times, it will be difficult to obtain the strength to withstand external stress.

  Moreover, in order to accelerate the curing rate of the first foamed solid lubricant, a tertiary amine catalyst, an organometallic catalyst, or the like can be used. Examples of the tertiary amine catalyst used include monoamines, diamines, triamines, cyclic amines, alcohol amines, ether amines and the like. Examples of the organometallic catalyst include stanaoctaate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin maleate, dioctyltin dimercaptide, dioctyltin thiocarboxylate and the like. Moreover, you may mix and use these multiple types for the purpose of adjusting the balance of reaction.

In the present invention, the urethane prepolymer that can be used as the resin component of the second foamed solid lubricant is obtained by a reaction between a compound having an active hydrogen group and a polyisocyanate, and the isocyanate group may be a molecular chain terminal, or It may be contained at the end of the side chain branched from the molecular chain. The urethane prepolymer may have a urethane bond in the molecular chain.
Depending on the type of monomer (= compound having an active hydrogen group) to be reacted, it is classified into caprolactone, ester and ether. Ether ethers include Takenate L-1170 (Mitsui Chemical Polyurethane), L-1158 (Mitsui Chemical Polyurethane), and Coronate 4090 (Nippon Polyurethane). Coronate 4047 (manufactured by Nippon Polyurethane Co., Ltd.) is used as the ester system, and Takenate L-1350 (manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.), Takenate L-1680 (manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.), and Sianaprene 7-QM are used as caprolactones. (Manufactured by Mitsui Chemicals Polyurethane), Plaxel EP1130 (manufactured by Daicel Chemical Industries) and the like.
Moreover, the oligomer and prepolymer compound which modified the terminal group into the isocyanate group can also be used. Examples of such a compound include a terminal isocyanate-modified polyether polyol and an isocyanate-modified product of a hydroxyl group-terminated polybutadiene. Examples of the terminal isocyanate-modified polyether polyol include Coronate 1050 (manufactured by Nippon Polyurethane Co., Ltd.). Moreover, poly-bd MC50 (made by Idemitsu Kosan Co., Ltd.) and poly-bd HTP9 (made by Idemitsu Kosan Co., Ltd.) are mentioned as the isocyanate modified body of hydroxyl-terminated polybutadiene.
These urethane prepolymers can be used in a mixture of two or more depending on the intended mechanical properties.

As the second foamed solid lubricant, a urethane prepolymer having an isocyanate group content of 2 wt% or more and less than 6 wt% can be used. If the isocyanate group (NCO) content is less than 2% by weight, it will be difficult to achieve both foamability and elasticity, and if it is more than 6% by weight, the hardness will be too high and the rebound resilience will increase and deformation due to external force will occur. It becomes easy to generate heat when receiving.
Moreover, the isocyanate group can use the block isocyanate etc. which blocked the isocyanate group with blocking agents, such as phenols, lactams, alcohols, and oximes.

The curing agent for curing the urethane prepolymer is preferably a compound having active hydrogen, and examples thereof include a polyamino compound having a functional group as an amino group and a polyol compound having a functional group as a hydroxyl group.
Polyamino compounds include 3,3'-dichloro-4,4'-diaminodiphenylmethane (hereinafter referred to as MOCA), 3,3'-dimethyl-4,4'-diaminodiphenylmethane, and 3,3'-dimethoxy-4. , 4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, trimethylene-bis- (4-aminobenzoate), bis (methylthio) -2,4- Aromatics typified by toluenediamine, bis (methylthio) -2,6-toluenediamine, methylthiotoluenediamine, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine Examples include polyamino compounds.

  Among the polyamino compounds, aromatic amino compounds are preferable because of low cost and excellent physical properties, and aromatic diamino compounds having a substituent at the position adjacent to the amino group are particularly preferable. In the 2nd foaming solid lubricant, since it passes through the process of hardening with foaming, it is thought that the reactivity of an amino group is suppressed by the substituent of an adjacent position.

  When the urethane prepolymer is cured with a polyamino compound, it becomes a foamed solid lubricant having urethane and urea bonds in the molecule. By generating urea bonds, the urethane bond density in the molecule is lowered, and elongation and impact resilience are improved. Moreover, rigidity can be provided by generating a urea bond.

  Examples of the polyol compound include low molecular polyols such as 1,4-butane glycol and trimethylolpropane, polyether polyols, castor oil polyols, and polyester polyols. Among the polyol compounds, polyether polyol and trimethylolpropane are preferable.

The ratio of the isocyanate group (—NCO) contained in the urethane prepolymer and the functional group of the curing agent that reacts with the isocyanate group is an equivalent ratio when the functional group is an amino group or a hydroxyl group (functional group of the curing agent). /NCO)=1/(1.1 to 2.5).
The ratio of the isocyanate group contained in the urethane prepolymer, the amino group (—NH ₂ ) or hydroxyl group (—OH) of the curing agent, and the hydroxyl group of water (—OH) as the foaming agent, Flexibility, elasticity, etc. are determined. When the amino group (—NH ₂ ) or hydroxyl group (—OH) of the curing agent is reacted with the isocyanate group (—NCO) of the urethane prepolymer in an equivalent amount, an isocyanate group (—NCO) that reacts with water as the foaming agent is formed. Since it will disappear, the range of (functional group of curing agent / NCO) = 1 / (1.1 to 2.5) is preferable. Moreover, the ratio of the hydroxyl group of water which is a foaming agent and the functional group of a hardening | curing agent is the range of (hydroxyl group of water / functional group of a hardening | curing agent) = 1 / (0.7-2.0) by an equivalent ratio.
If the amount of the curing agent is less than the above range, not only the physical properties such as the strength of the foamed solid lubricant are remarkably lowered, but also the urethane elastomer may not be cured.

The lubricating component that can be used in the second foamed solid lubricant can be used as long as it does not dissolve the solid component that forms the foam, like the first foamed solid lubricant. As the lubricating component, for example, lubricating oil, grease, wax or the like can be used alone or in combination. Particularly preferred are hydrocarbon-based lubricants, hydrocarbon-based greases, or mixtures of hydrocarbon-based lubricants and hydrocarbon-based greases.
As the hydrocarbon-based lubricant, the same one as the first foamed solid lubricant can be used. In addition, ester synthetic oils, ether synthetic oils, fluorine oils, silicone oils and the like can also be used. These can be used alone or as a mixed oil.
As the grease, in addition to the grease similar to the first foamed solid lubricant, a grease based on ester synthetic oil, ether synthetic oil, GTL base oil, fluorine oil, silicone oil or the like can be used.
In addition, the same hydrocarbon-based synthetic wax, polyethylene wax, higher fatty acid ester-based wax, higher fatty acid amide-based wax, ketone / amines, hydrogenated oil, and the like as the first foamed solid lubricant may be used. it can.

As the foaming agent for foaming the second foamed solid lubricant, since an isocyanate compound is used as a raw material, it is preferable to use water that reacts with the isocyanate compound to generate carbon dioxide gas.
Moreover, in order to accelerate the curing rate of the second foamed solid lubricant, the above-described tertiary amine catalyst, organometallic catalyst, or the like can be used.

The second foamed solid lubricant is obtained by foaming and curing a mixture containing the lubricating component, the resin component, the curing agent, and the foaming agent.
The blending ratio of the lubricating component is 30 to 70% by weight, preferably 40 to 60% by weight, based on the entire mixture. If the lubricating component is less than 30% by weight, the supply amount of lubricating oil or the like is so small that it cannot function as a foamed solid lubricant, and if it exceeds 70% by weight, it may not solidify.

  The open cell ratio of the second foamed solid lubricant after foaming is 50% or more, preferably 50% or more and 90% or less. When the open cell ratio is less than 50%, the ratio of the resin component (solid component) lubricating oil temporarily taken up into the closed cells increases and may not be supplied to the outside when necessary. If it exceeds 90%, the oil retention of the lubricant will decrease and the amount of lubricant released will increase, which will be disadvantageous for long-term use, and the strength (durability) of the foamed solid lubricant itself will decrease. There is a fear.

The open cell ratio of the second solid foam lubricant can be calculated by the following procedure.
(1) The foamed solid lubricant that has been foam-cured is cut into an appropriate size to obtain sample A. The weight of sample A is measured.
(2) A is soxhlet washed (solvent: petroleum benzine) for 3 hours. Thereafter, the sample is left in a thermostatic bath at 80 ° C. for 2 hours to completely dry the organic solvent, and sample B is obtained. The weight of sample B is measured.
(3) The open cell ratio is calculated by the following procedure.
Open cell ratio = (1− (weight of resin component of sample B−weight of resin component of sample A) / weight of lubricating component of sample A) × 100
The resin component weight and the lubrication component weight of Samples A and B are calculated by multiplying the weights of Samples A and B by the composition charge ratio.
Lubricating components taken into discontinuous closed cells are not released to the outside by Soxhlet cleaning for 3 hours, so the weight of sample B is not reduced. The open cell ratio can be calculated as a result of the release of the lubricating component.

The first and second foamed solid lubricants may contain various additives such as pigments, antistatic agents, flame retardants, antifungal agents, reinforcing agents, inorganic fillers, anti-aging agents, and fillers as necessary. Can be added. Examples of the reinforcing agent include carbon black, white carbon, colloidal silica, and examples of the inorganic filler include calcium carbonate, barium sulfate, talc, clay, and meteorite powder.
In addition, solid lubricants such as molybdenum disulfide and graphite, friction modifiers such as organic molybdenum, oily agents such as amines, fatty acids, and fats, antioxidants such as amines and phenols, petroleum sulfonates, dinonylnaphthalene sulfone Antirust agents such as nates and sorbitan esters, extreme pressure agents such as sulfur and sulfur-phosphorus, antiwear agents such as organic zinc and phosphorus, metal deactivators such as benzotriazole and sodium nitrite, polymethacrylate, polystyrene Various additives such as a viscosity index improver such as

For the first and second foamed solid lubricants, it is possible to use a reactive impregnation method in which a foaming reaction and a curing reaction are simultaneously performed in the presence of a lubricating component such as a lubricating oil. It is desirable to achieve both elongation simultaneously. This is because the lubricant is uniformly impregnated into the foam formed in the foam during the foam formation stage, and the lubricant is occluded in the foamed / cured solid component, so that the lubricant is highly filled and the material properties It is considered that the high elongation of both is compatible.
On the other hand, after the foam is manufactured in advance, the post-impregnation method in which the lubricant is impregnated does not have sufficient lubricant holding power, and the lubricant is released in a short period of time and supplied when used for a long time. It becomes insufficient.

A method of mixing the mixture containing the lubricating component, the resin component, the curing agent, and the foaming agent is not particularly limited, and a commonly used agitator such as a Henschel mixer, a ribbon mixer, a juicer mixer, a mixing head, or the like. Can be mixed using.
Since the mixture is rapidly foamed and cured by the curing agent and the foaming agent, it is desirable to add the curing agent and the other components except the foaming agent to the stirrer and finally the curing agent and the foaming agent.
It is desirable that the above mixture use a surfactant such as a commercially available silicone-based foam stabilizer to uniformly disperse each raw material molecule. Further, the surface tension can be controlled by the type of the foam stabilizer, and the type of the generated bubbles can be controlled to open cells or closed cells. Examples of such surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, silicone surfactants, and fluorine surfactants.

The foamed solid lubricant in the roll neck axle box sealing device of the present invention may be foamed and cured after pouring a mixture containing a lubricating component and a resin component into the roll neck axle box sealing device. After foaming and curing in step 1, it can be post-processed into a desired shape by cutting or grinding, and incorporated in the apparatus.
In the present invention, the mixture is foamed because it is possible to easily fill any part of the device having a complicated shape, and there is no need for a molding die or a grinding process for obtaining a foamed molded product. -It is preferable to employ a method of pouring into the apparatus before curing and foaming / curing in the apparatus. By adopting this method, the manufacturing process is simplified and the cost can be reduced.

  It is preferable that the bubbles to be generated when foamed by foaming at the time of foaming / curing are open cells that communicate with each other, and the lubricating component can be directly removed from the surface of the resin via the open cells by external stress. This is to supply. In the case of closed cells that do not communicate with each other, the entire amount of lubricating oil in the solid component is temporarily isolated in the closed cells, making it difficult to move between the bubbles. May not be.

Examples 1 to 15 and Comparative Examples 1 to 4
The lubricating components, liquid rubber, curing agent, foaming agent, and catalyst used in Examples 1 to 15 and Comparative Examples 1 to 4 are shown below. In addition, () represents an abbreviation in the table.
Lubricating component Lubricating oil (lubricating oil): Turbine 100 (manufactured by Nippon Oil Corporation)
Lubricating grease (Grease 1): NTG2218M (manufactured by Kyodo Yushi Co., Ltd.)
Liquid rubber Hydroxyl-terminated polybutadiene (PBOH1): Poly-bd R45HT (hydroxyl value: 46.6 mg KOH / g, number average molecular weight: 2,800, manufactured by Idemitsu Kosan Co., Ltd.)
Hydroxyl-terminated polybutadiene (PBOH2): Poly-bd R15HT (hydroxyl value: 102.7 mg KOH / g, number average molecular weight: 1,200, manufactured by Idemitsu Kosan Co., Ltd.)
Hydroxyl-terminated polyisoprene (PipOH): Poly-ip (hydroxyl value: 46.6 mg KOH / g, number average molecular weight: 2,500, manufactured by Idemitsu Kosan Co., Ltd.)
Hydrogenated hydroxyl-terminated polyisoprene (HPipOH): Epol (hydroxyl value: 50.5 mg KOH / g, number average molecular weight: 2,500, manufactured by Idemitsu Kosan Co., Ltd.)
Curing agent Isocyanate compound (TDI): Coronate T-80 (manufactured by Nippon Polyurethane Co., Ltd.)
Elastomer 1 (UE1): Coronate 4090 (4.4 NCO% made by Nippon Polyurethane)
Elastomer 2 (UE2): Plaxel EP1130 (3.3 NCO% manufactured by Daicel Chemical Industries)
Foaming agent (foaming agent) Ion exchange water foam stabilizer (foam stabilizer) SRX298 (manufactured by Toray Dow)
Catalyst (Catalyst 1) DM70 (manufactured by Tosoh Corporation)

Mix well the compounding materials except the curing agent (isocyanate) at the blending ratios shown in Tables 1 to 3, and finally add 40 g of the mixture that was quickly mixed by adding the curing agent to a polytetrafluoroethylene resin container (70 mm in diameter). × Height 150 mm). After a few seconds, the foaming reaction started and allowed to stand at room temperature for several hours to be cured to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant that is an elastic rubber foam that exudes oil when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. Further, when not cured as a foam, cases where the lubricating oil does not separate or release are marked with “x” and are also shown in Tables 1 to 3.
In addition, the test piece evaluated as “◯” showed no oil oozing even when it was stretched 20% in the direction of the cylinder axis of the test piece.

As shown in Tables 1 to 3, the foamed solid lubricants of Examples 1 to 15 are elastic rubber foams in which oil oozes out when a corresponding force is applied when pressed with a finger. Although it was recognized as an excellent foamed solid lubricant, in Comparative Examples 1 to 4, it was found that although foamed, it did not partially solidify and function as a foamed solid lubricant.
Next, the foamed solid lubricant components of Examples 1 to 15 were surrounded by the fillet ring 3 of the sealing device for the roll neck axle box shown in FIG. 1, the bearing cover 7, and the seals 8, 9, and 10. It was poured into a space and allowed to stand at room temperature for several hours to be cured, thereby obtaining a roll neck shaft box sealing device in which a foamed solid lubricant was enclosed.
Since this roll neck shaft box sealing device is sealed with foamed solid lubricant inside the device, it becomes a self-lubricating roll neck shaft box sealing device, which eliminates the need to supply a seal lubricant from the outside. .

The lubricating components, urethane prepolymers, curing agents, foaming agents, and catalysts used in Examples 16 to 35 and Comparative Examples 5 to 7 are shown below. In addition, () represents an abbreviation in the table.
Lubricating component Lubricating oil (lubricating oil 1): Turbine 100 (paraffinic mineral oil, manufactured by Nippon Oil Corporation)
Lubricating oil (lubricating oil 2): Crisef 150 (Naphthenic mineral oil, manufactured by Nippon Oil Corporation)
Lubricating oil (lubricating oil 3): Shin fluid 801 (poly-α-olefin, manufactured by Nippon Steel Chemical Co., Ltd.) Lubricating grease (grease 2): Pyronic Universal N6C (manufactured by Nippon Oil Corporation)
Urethane prepolymer Caprolactan-based urethane prepolymer 1 (prepolymer 1): Plaxel EP1130 (NCO 3.3%, manufactured by Daicel Chemical Industries)
Ether-based urethane prepolymer (Prepolymer 2): Coronate 4090 (NCO 4.3%, manufactured by Nippon Polyurethane)
Ester urethane prepolymer (Prepolymer 3): Coronate 4047 (NCO 4.3%, manufactured by Nippon Polyurethane Co., Ltd.)
Caprolactan urethane prepolymer (Prepolymer 4): Takenate L-1350 (NCO 2.3%, manufactured by Mitsui Chemicals Polyurethanes)
Ether-based urethane prepolymer (Prepolymer 5): Takenate L-1170 (NCO 2.4%, manufactured by Mitsui Chemicals Polyurethanes)
Caprolactan urethane prepolymer (Prepolymer 6): Takenate L-1680 (NCO 3.2%, manufactured by Mitsui Chemicals Polyurethanes)
Caprolactan urethane prepolymer (Prepolymer 7): Cyanaprene 7-QM (NCO 2.3%, manufactured by Mitsui Chemicals Polyurethanes)
Ether-based urethane prepolymer (Prepolymer 8): Takenate L-1158 (NCO 4.4%, manufactured by Mitsui Chemicals Polyurethanes)
Hardener MOCA (MOCA): Iharacamine MT (manufactured by Ihara Chemical)
Trimethylene-bis- (4-aminobenzoate) (CUA-4): CUA-4 (manufactured by Ihara Chemical)
Mixture of bis (methylthio) -2,4-toluenediamine, bis (methylthio) -2,6-toluenediamine and methylthiotoluenediamine (Etacure 300): Etacure 300 (manufactured by Albemarle)
Trimethylolpropane: Reagent blowing agent (foaming agent) Ion exchange water foam stabilizer (foam stabilizer) SRX298 (manufactured by Toray Dow)
Catalyst (Catalyst 1) DM70 (manufactured by Tosoh Corporation)

Examples 16-18, 21, 22, 24, 25, 27-32, 34-35, Comparative Examples 5-7
In a polytetrafluoroethylene beaker (diameter 70 mm × height 150 mm) at 80 ° C., the raw materials excluding the curing agent, amine catalyst and blowing agent were mixed well in the blending ratios shown in Tables 4 to 6. Next, MOCA dissolved at 120 ° C. was put into a beaker and well stirred. Subsequently, an amine catalyst and a foaming agent (only Comparative Example 6 had no foaming agent) were added and stirred. After a few seconds, the foaming reaction started, and it was allowed to stand at 100 ° C. for 30 minutes to cure to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant that is an elastic rubber foam that exudes oil when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. In other cases, “Δ” mark or comments are also shown in Tables 4 to 6.
Further, the open cell ratio was measured by the above-described method, and the centrifugal oil separation evaluation was measured by the following method. The results are shown in Tables 4-6.
Centrifugal oil separation evaluation test Centrifugal oil separation was measured in order to examine the sustained release of the lubricant. Centrifugal oil separation showed the oil reduction rate relative to the oil filling amount when rotated for 1 hour under the conditions of a rotor radius of 75 mm and a rotation speed of 1500 rpm.

Example 19
In a polytetrafluoroethylene beaker (diameter 70 mm × height 150 mm) at 100 ° C., the raw materials excluding the curing agent, amine catalyst and blowing agent were mixed well in the blending ratio shown in Table 4. Next, trimethylene-bis (4-aminobenzoate) dissolved at 140 ° C. was put into a beaker and stirred well. Subsequently, an amine catalyst and a blowing agent were added and stirred. After a few seconds, the foaming reaction started, and it was allowed to stand at 100 ° C. for 30 minutes to cure to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant that is an elastic rubber foam that exudes oil when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. Is also shown in Table 4.

Examples 20, 26, 33
In a polytetrafluoroethylene beaker (diameter 70 mm × height 150 mm) at 80 ° C., the raw materials excluding the curing agent, amine catalyst and blowing agent were mixed well in the blending ratios shown in Tables 4 to 6. Next, Etacure 300 was put into a beaker and stirred well. Subsequently, an amine catalyst and a blowing agent were added and stirred. After a few seconds, the foaming reaction started, and it was left to cure at 100 ° C. for 30 minutes to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant that is an elastic rubber foam that exudes oil when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. Are also shown in Tables 4-6.

Example 23
In a polytetrafluoroethylene beaker (diameter 70 mm × height 150 mm) at 100 ° C., raw materials excluding the curing agent, amine catalyst and blowing agent were mixed well in the blending ratio shown in Table 5. Next, trimethylolpropane was put into the beaker and stirred well. Subsequently, an amine catalyst and a blowing agent were added and stirred. After a few seconds, the foaming reaction started, and it was allowed to stand at 100 ° C. for 30 minutes to cure to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant that is an elastic rubber foam that exudes oil when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. Is also shown in Table 5.

As shown in Tables 4 to 6, Examples 16 to 35 are elastic rubber foams in which oil oozes out when a corresponding force is applied when pressed with a finger, and excellent foam solid lubrication. In Comparative Example 5, it was found that although foamed, it did not partially solidify, and in Comparative Example 6, the resin component and the lubricant were separated and did not function as a foamed solid lubricant. . Comparative Example 7 lacked elasticity. Further, in Examples 16 to 35, it was found that the lubricant component was gradually released under the centrifugal force (without immediately leaving the foam).
Next, the foamed solid lubricant components of Examples 16 to 35 were surrounded by the fillet ring 3 of the sealing device for the roll neck axle box shown in FIG. 1, the bearing cover 7, and the seals 8, 9, and 10. It was poured into the space and allowed to stand at 100 ° C. for 30 minutes to be cured, thereby obtaining a sealing device for a roll neck axle box in which a foamed solid lubricant was enclosed.
Since this roll neck shaft box sealing device is sealed with foamed solid lubricant inside the device, it becomes a self-lubricating roll neck shaft box sealing device, which eliminates the need to supply a seal lubricant from the outside. .

  Since the sealing device for roll neck axle box of the present invention encloses the foamed solid lubricant inside, the lubricant is gradually released to the seal sliding contact portion during operation, so that it is not necessary to supply the seal lubricant from the outside. Self-lubricating. For this reason, it can utilize suitably for the sealing device for roll neck axis boxes.

It is sectional drawing which shows one Example of the sealing apparatus for roll neck axle boxes of this invention. It is a figure which shows the structure around the roll neck of a rolling mill.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Roll neck shaft box sealing device 2 Roll 2a Roll neck 2b Shaft end 3 Fillet ring 4, 5 Bearing device 6 Shaft box 7 Bearing cover 8, 9, 10 Seal 8a Seal lip portion 8b Metal ring 11 Foam solid lubricant 12 Spring

Claims (11)

It is interposed between a fillet ring fixed to the outer periphery of the roll neck and a bearing cover provided to be connected to a shaft box of a bearing device that rotatably supports the roll neck, and an inner diameter side slides on the outer periphery of the fillet ring. A roll neck shaft box sealing device comprising a double-row seal that is in contact with the outer diameter side and is fixed to the bearing cover;
A foamed solid lubricant obtained by foaming and curing a mixture containing a lubricating component, a resin component, a curing agent, and a foaming agent in a space surrounded by the fillet ring, the bearing cover, and the seal. A sealing device for a roll neck shaft box, characterized by being sealed. The lubricating component is at least one lubricating component selected from a hydrocarbon-based lubricating oil and a hydrocarbon-based grease;
The resin component is a liquid rubber in which the polymer main chain is composed of hydrocarbons and has hydroxyl groups in an amount such that the hydroxyl value is 25 to 110 mg KOH / g at the ends of the main chain.
The curing agent is an organic compound having an isocyanate group in the molecule,
The blowing agent is water;
The ratio of the liquid rubber and the curing agent is such that the hydroxyl group contained in the liquid rubber and the isocyanate group contained in the curing agent are in an equivalent ratio of (OH / NCO) = 1 / (1.0 to 2.0). ,
2. The sealing device for a roll neck axle box according to claim 1, wherein the mixture contains 40 to 80% by weight of the lubricating component and 5 to 45% by weight of the liquid rubber with respect to the whole mixture.   The liquid rubber is a hydroxyl group-terminated diene polymer having a number average molecular weight of 1000 to 3,500 having a hydroxyl group at the main chain end of a butadiene or isoprene polymer, or a modified hydroxyl group-terminated diene polymer obtained by hydrogenating the diene polymer. The sealing device for a roll neck shaft box according to claim 2, wherein:   The organic compound having an isocyanate group in the molecule is a prepolymer having two or more isocyanate groups in the molecule and a ratio of isocyanate groups of 2.5 to 5.0 NCO%. The sealing device for roll neck shaft boxes according to claim 3.   4. The sealing device for a roll neck axle box according to claim 2, wherein the organic compound having an isocyanate group in the molecule is an aromatic polyisocyanate. The lubricating component is at least one lubricating component selected from lubricating oil and grease;
The resin component is a urethane prepolymer having an isocyanate group content of 2 wt% or more and less than 6 wt%,
The blowing agent is water;
The said mixture contains 30 to 70 weight% of said lubrication components with respect to the whole mixture, and the open cell ratio after foaming is 50% or more, The sealing device for roll neck shaft boxes of Claim 1 characterized by the above-mentioned. .   The roll neck axle box according to claim 6, wherein the urethane prepolymer is at least one urethane prepolymer selected from an ester urethane prepolymer, a caprolactone urethane prepolymer, and an ether urethane prepolymer. Sealing device.   The ratio of the isocyanate group and the functional group of the curing agent that reacts with the isocyanate group is an equivalent ratio (functional group of the curing agent / NCO) = 1 / (1.1 to 2.5). The roll neck axle box sealing device according to claim 6 or 7.   The ratio of the hydroxyl group of the water and the functional group of the curing agent is an equivalent ratio (water hydroxyl group / functional group of the curing agent) = 1 / (0.7 to 2.0). The roll neck shaft box sealing device according to claim 8.   The roll neck shaft box sealing device according to any one of claims 6 to 9, wherein the curing agent is an aromatic polyamino compound.   The sealing device for a roll neck shaft box according to claim 10, wherein the aromatic polyamino compound is an aromatic polyamino compound having a substituent at a position adjacent to an amino group.

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