JP2008184621A - Sealing agent, member coated with thermally sprayed coating, and bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing agent which is excellent in the penetration property and the filling property into pores (voids) and with which it is possible to attain such sealing state that substantially all of the voids of a thermally sprayed coating are filled; and to provide a member coated with a thermally sprayed coating. <P>SOLUTION: The sealing agent for a thermally sprayed coating comprises epoxy group-containing components, a curing agent for the epoxy group-containing components and a hydroxyl group-containing vinyl ether compound, and is free from polymerizable vinyl group-containing solvents except the hydroxyl group-containing vinyl ether compound, wherein the hydroxyl group-containing vinyl ether compound is incorporated in an amount of 10-30 wt.% based on the whole of the epoxy-containing components. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sealing agent, a thermal spray coating member, and a bearing, and more particularly, to an epoxy resin-based sealing agent, and a thermal spray coating member and a bearing obtained by treatment with the processing agent.

  A technique for improving the heat resistance, wear resistance, and corrosion resistance by spraying hard particles and powders such as metals or ceramics on the surface of a base material of a machine part composed of steel or the like has been practiced. In general, the thermal spray coating has pores such as voids, gaps, and voids generated in the process of forming the coating, and these pores impart various characteristics to the coating itself. Some of the pores show the form of communication holes that lead from the substrate surface to the substrate substrate, and communicate the environment where the coating surface layer is in contact with the substrate on which the coating is coated. Through this communication hole, a phenomenon is observed in which a gas or liquid in contact with the outside of the thermal spray coating permeates or diffuses to the base material. As a result, when the thermal spray material itself deteriorates due to corrosion, or when the base substrate is carbon steel or the like, the substrate selectively deteriorates at the contact interface between the coating and the substrate, and the spray coating is bonded to the substrate. It may lose its properties and peel off. In addition, ceramic spraying may be performed for the purpose of ensuring insulation between the machine part main body and the member on which it is installed / provided, but the dielectric breakdown is caused by the above-mentioned gas and liquid penetration diffusion phenomenon, In some cases, the desired insulation resistance may not be exhibited.

  Therefore, after forming a sprayed coating, some sealing treatment has been performed to perform a sealing treatment that enhances the environmental barrier properties of the coating. As a general well-known sealing treatment method, a method of applying a sealing treatment agent in which a synthetic resin such as an epoxy resin, an acrylic resin, a urethane resin, a phenol resin, or a fluororesin is dissolved in an organic solvent is applied to the spray coating. There is. However, in this method, it is only applied to the surface of the sprayed coating and does not penetrate to the bottom of the pores. Therefore, when the surface of the sprayed coating is removed by grinding or polishing after the sealing treatment in order to maintain the shape (dimension) accuracy, the sealing treatment effect on the sprayed coating may be hardly expected. In addition, there are cases where the coating film of the synthetic resin is worn away due to wear in the process of use, and the effect of the sealing treatment is not sustained.

On the other hand, attempts are often made to improve the adhesion between the metal substrate and the thermal spray coating material by applying a sealing treatment.
A general thermal sprayed coating does not form a chemical bond with the surface on which the coating is to be formed, but a mechanical fastening force (referred to as an anchoring effect, anchoring effect, etc.) and the base material. Consistency of contact. In particular, when spraying is applied to the surfaces of mechanical parts made of metal substrates such as gears, bearings, and spindles, where the dimensional accuracy is severely demanded, the surfaces of these machine parts are often polished and the surface roughness Ra is less than 1 μm. In many cases. Therefore, when spraying the surfaces of these metal parts, a process of increasing the surface roughness Ra to about 1 μm or more is often performed by a known surface modification method such as shot blasting or tumbling. This technique can improve the adhesion between the thermal spray coating and the substrate to some extent, but depending on the degree of surface modification, the dimensional accuracy of the substrate may deteriorate or the surface layer may be annealed. Defects such as deterioration of physical properties of the base material may occur. As a result, there is a limit to the method for improving the adhesion by this method.

  Therefore, efforts have been made to use chemical adhesion in combination to assist physical adhesion. However, in the general sealing treatment method described above, the coating is only applied to the surface of the sprayed coating. Since it does not penetrate to the base material interface at the bottom of the hole, it only increases the adhesion between the ceramic particles near the outermost surface of the thermal spray coating, and the chemical adhesion between the metal base and the thermal spray coating material. It does not reach the power.

As a method for improving these, for example, a method of using a photocurable resin that is cured by visible light as a sealing agent (see Patent Document 1), an electro-deposition paint, and an electrophoretic phenomenon of paint particles, A method of depositing and filling pores (see Patent Document 2), spraying a sprayed material added with B ₂ O ₃ forming a vitreous substance on the surface of the base material, and then heating the sprayed coating to form B _{A method} of melting ₂ O ₃ and filling a gap generated in the sprayed coating (see Patent Document 3), adding B ₂ O ₃ forming a vitreous substance in the sprayed material to form a coating, There are known ones in which molten B ₂ O ₃ performs pore filling in the subsequent heat treatment (see Patent Document 3). However, these methods have a problem that they are not suitable for industrial production methods, such as requiring special equipment and complicated steps in addition to the pressurization or decompression step.

  Therefore, the essential composition of the sealing agent is at least selected from the group consisting of (i) a synthetic resin, (ii) a polymerizable organic solvent, and (iii) a fluorosurfactant and a perfluoro group-containing organosilicon compound. A method of containing one kind is known (see Patent Document 4). This method is intended to form a cured product when (i) the synthetic resin is cured, ((ii) the polymerizable organic solvent alone or in combination with (i) the synthetic resin). However, (ii) only by simple heating of the polymerizable organic solvent, dissolved oxygen or the like in the solution inhibits the polymerization, so that it is difficult to actually cure the solvent portion. In particular, when “styrene monomer”, which is a typical vinyl group-containing organic compound as shown in Examples of Patent Document 4, is used as a polymerizable solvent, the polymerization reaction is not sufficiently performed at the curing temperature of the epoxy resin. The unreacted polymerizable solvent remains in the epoxy resin, and there is concern about the long-term stability of the sealing resin after curing. For the purpose of accelerating the polymerization reaction of the polymerizable solvent, a radical polymerization initiator or the like is blended as described in Patent Document 4, while the oxygen dissolved in the sealing agent system is highly removed. Is required. However, high temperature type radical polymerization initiators are generally composed of organic peroxides that are highly reactive and have a high risk of explosion, and therefore, care must be taken in handling. On the other hand, if a low temperature type polymerization initiator is selected, such concerns are alleviated. However, since the decomposition reaction of the polymerization initiator proceeds even at a low temperature, it is necessary to pay attention to the pot life of the uncured sealing agent. In addition, from the viewpoint of the amount of dissolved oxygen, there is a problem that it is always required to observe detailed precautions in order to enhance storage stability.

As described above, in the prior art, even if the sealing agent is permeated to the surface of the base material, there are concerns due to blending the polymerizable solvent into the epoxy resin.
On the other hand, epoxy resins obtained by reacting isocyanates, hydroxyvinyl ethers and glycidols as toughened urethane-modified epoxy resins used for flexible wiring board materials, build-up materials for semiconductor packages, and peripheral materials for liquid crystal displays. It is known (see Patent Document 5).
However, these hydroxy vinyl ethers are blended in order to form the resin skeleton of urethane-modified epoxy resin, and do not contribute to lowering the viscosity or increasing the penetration of the sealing agent.
JP-A-5-106014 JP-A-6-212391 JP-A-10-259469 Japanese Patent Laid-Open No. 2003-183806 JP 2006-111809 A

  The present invention has been made in order to cope with such problems, and has excellent permeability and filling ability to pores (gap), and sealing treatment is performed until substantially all gaps of the thermal spray coating material are filled. A sealing agent and a sealing method that can be applied and avoid deterioration of sealing characteristics over time, and there is a sufficient penetration / filling layer of the sealing agent even after being removed by grinding or polishing. It is an object of the present invention to provide a thermal spray coating member capable of improving physical properties such as mechanical properties and electrical properties, and a bearing using the same.

The sealing agent of the present invention contains an epoxy group-containing component, a curing agent for the epoxy group-containing component, and a hydroxyl group-containing vinyl ether compound, and does not contain a polymerizable vinyl group-containing solvent other than the hydroxyl group-containing vinyl ether compound. A sealing agent for thermal spray coating, wherein the hydroxyl group-containing vinyl ether compound is blended in an amount of 10 to 30% by weight based on the total epoxy group-containing component.
In addition, the epoxy group-containing component is a polyglycidyl ether compound having 3 or more epoxy groups contained in one molecule as an essential component, and alkylene diglycidyl having 2 epoxy groups contained in one molecule. A mixture containing at least one selected from an ether compound and a cycloaliphatic diepoxy compound, wherein the polyglycidyl ether compound is blended in an amount of 10 to 80% by weight based on the whole epoxy group-containing component excluding the curing agent. It is characterized by being.
The epoxy group-containing component further includes a monoglycidyl ether compound having one epoxy group in one molecule.
The thermal spray coating member of the present invention is a thermal spray coating member having a thermal spray coating sealed with the above-described sealing agent on a metal substrate.
The bearing according to the present invention is characterized in that the thermal spray coating member is formed on the surface of the bearing constituent member.

The sealing agent of the present invention comprises a mixture of 70 to 90% by weight of an epoxy group-containing component having an extremely low viscosity and 10 to 30% by weight of a hydroxyl group-containing vinyl ether compound which is also a very low viscosity solvent. Since it has a composition with a liquid curing agent added, the sealant mixture has a very low viscosity, which is equivalent to a sealant with a low viscosity using a conventional polymerizable / non-polymerizable solvent. The above permeability can be secured. Further, by using the present compound as an additive, the evaporation loss can be greatly reduced, so that the voids of the sprayed film after the sealing treatment are effectively filled with the resin. Furthermore, by using this compound as an additive, the reactivity of the system is greatly improved, and the thermosetting conditions can be relaxed.
Since the epoxy group-containing component is a mixture containing a predetermined polyglycidyl ether compound as a main component, the generation of voids due to the volatilization of the solvent in the sealing agent is effectively suppressed, and the gap between the sprayed coating materials is substantially reduced. The sealing process can be performed until all of them are filled.
In addition, since a mixture of a plurality of polyglycidyl ether compounds has a similar molecular structure and is excellent in compatibility, there is no possibility of phase separation or the like, so that it can easily penetrate into pores. For this reason, it is possible to avoid the possibility of deterioration of the sealing state of the sprayed coating material and the sealing characteristics over time, prevent damage such as peeling of the sprayed coating during use, and improve the life of the machine parts.

  In addition, since the thermal spray coating member of the present invention is formed using the above-mentioned sealing agent, it has excellent permeability and filling properties with respect to pores (gap) of the thermal spray coating, and the surface layer portion of the thermal spray coating is ground after the sealing treatment. Or even if it is removed by polishing, there is a sufficient penetration / filling layer of the sealing agent, and as a result, the substrate protection of the film can be greatly improved, and further physical properties such as mechanical properties and electrical properties can be improved. Can be used for bearings.

As a result of intensive investigations on a sealing agent that can prevent deterioration of the sealing properties of the thermal spray coating material and breakage of the thermal spray coating during use, the number of epoxy groups contained in one molecule is different as an epoxy group-containing component. The thermal spray coating that has been sealed using a sealing agent containing a hydroxyl group-containing vinyl ether compound together with a mixture of a polyglycidyl ether compound or the like has pores ( It has excellent permeability and filling ability to the gap), and even if the surface layer of the thermal spray coating is ground or polished after the sealing treatment, there is a sufficient penetration / filling layer of the sealing agent, resulting in the protection of the base material of the coating. It has been found that the physical properties such as mechanical properties and electrical properties can be improved significantly.
This is because the sealing agent that has penetrated the particle boundary due to its excellent permeability and filling property properly fills the particle boundary, firmly adheres to the particle boundary due to its excellent adhesive force, and has a highly volatile polymerizable vinyl group. Because it does not contain the contained solvent, by effectively suppressing the generation of voids due to the volatilization of the solvent, it is possible to perform the sealing treatment until the gap of the thermal spray coating material is substantially all filled Conceivable. The present invention has been completed based on such findings.

  The sealing agent of the present invention includes a hydroxyl group-containing vinyl ether compound in which functional groups contained in one molecule are at least a hydroxyl group and a vinyl group, and a polyglycidyl ether compound having 3 or more epoxy groups contained in one molecule. In addition to this essential component, an alkylene diglycidyl ether compound having two epoxy groups contained in one molecule and / or a cyclic fat having two epoxy groups contained in one molecule It is a mixture containing a group diepoxy compound. A polyglycidyl ether compound and a cycloaliphatic diepoxy compound are compounds that do not contain a repeating unit formed by cleavage of an oxirane ring in the molecule. The mixture of the present invention reacts with a curing agent to form a cured product.

Examples of the hydroxyl group-containing vinyl ether compound include 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, hydroxymethyl vinyl ether, hydroxypropyl vinyl ether, hydroxypentyl vinyl ether, hydroxyhexyl vinyl ether, hydroxyheptyl vinyl ether, hydroxyoctyl vinyl ether, hydroxynonyl vinyl ether. 4-hydroxycyclohexyl vinyl ether, 3-hydroxycyclohexyl vinyl ether, 2-hydroxycyclohexyl vinyl ether, cyclohexanedimethanol monovinyl ether, diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, tetraethyleneglycol Such as mono-vinyl ether. Among these, the viscosity of the sealing agent can be lowered, the compound itself has a low viscosity, and the solvent volatilization due to an exothermic reaction during thermosetting can be suppressed, and the boiling point of the compound is high. A diethylene glycol monovinyl ether compound that can prevent deterioration of the working environment and has extremely low irritation to the biological mucous membrane is preferable.
The hydroxyl group-containing vinyl ether compound also acts as a diluent.

  The hydroxyl group-containing vinyl ether compound is blended in an amount of 10 to 30% by weight based on the entire epoxy group-containing component excluding the curing agent. Preferably it is 15-25 weight%. When it is less than 10% by weight, the effect of reducing the viscosity of the sealing agent is low, and the effect of improving the permeability of the sealing agent cannot be obtained. On the other hand, when the compounding ratio of the hydroxyl group-containing vinyl ether compound exceeds 30% by weight, the concentration of the epoxy compound, which is the active ingredient of the sealing agent, becomes relatively low, so the heat resistance of the cured product and the adhesion to the substrate However, there is a concern that the sealing ability is lowered as a result.

Examples of the polyglycidyl ether compound having 3 or more epoxy groups contained in one molecule include triglycidyl ether compounds and tetraglycidyl ether compounds.
Examples of the polyglycidyl ether compound include trimethylolpropane polyglycidyl ether, glycerol triglycidyl ether, and sorbitol polyglycidyl ether.
Among these, from the viewpoint of lowering the viscosity of the sealing agent, a triglycidyl ether compound is preferable, and trimethylolpropane polyglycidyl ether is particularly preferable.

  Examples of the alkylene diglycidyl ether compound having two epoxy groups contained in one molecule include neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,6- Mention may be made of hexanediol diglycidyl ether.

The cycloaliphatic diepoxy compound having two epoxy groups contained in one molecule is a so-called alicyclic compound in which two adjacent carbon atoms form an oxirane ring. Examples of the alicyclic epoxy compound include alicyclic diepoxy compounds containing two oxirane rings, such as 1,2,8,9-diepoxy limonene. It is a preferred compound that effectively prevents the physical properties of the treated product from being lowered while lowering the viscosity of the sealing agent.
Further, diglycidyl ethers of alicyclic compounds such as hydrogenated bisphenol A and diglycidyl ether of tetrahydrophthalic acid can also be used.

The sealing agent of the present invention contains a monoglycidyl ether compound having one epoxy group contained in one molecule for the purpose of improving the handleability and further improving the permeability to the spray coating material. be able to.
Examples of the monoglycidyl ether compound having one epoxy group contained in one molecule include known monoglycidyl ether compounds such as alkyl monoglycidyl ethers such as butyl glycidyl ether and alkylphenol monoglycidyl ethers.

The triglycidyl ether compound can be used as a sealing agent component that dramatically increases the adhesion between the thermal spray coating and the metal substrate. At the same time, since the viscosity of the compound itself is low, it is not necessary to add an organic solvent such as xylene and methyl ethyl ketone or a polymerizable vinyl group-containing solvent by mixing with a diglycidyl ether compound, which will be described later. In contrast, sufficient permeability can be imparted.
In addition, when the amount of chlorine ions contained in the resin is 0.5% by weight or less, it is possible to suppress deterioration of electrical characteristics such as insulation resistance in a humid atmosphere and corrosivity of the base material.
The viscosity of the triglycidyl ether compound at 25 ° C. is preferably 500 mPa · s or less. If it exceeds 500 mPa · s, the permeability is poor.

  The blending ratio of the triglycidyl ether compound is preferably 10 to 80% by weight, more preferably 20 to 50% by weight, based on the entire mixture. If it is less than 10% by weight, the viscosity of the sealing liquid itself can be set low. The adhesive strength of is reduced. Further, when the blending ratio of the triglycidyl ether compound exceeds 80% by weight, the permeability of the sealing agent is increased, so that the permeability is poor.

  Since the alkylene diglycidyl ether compound having two epoxy groups contained in one molecule is an epoxy compound having a low viscosity in itself, the viscosity of the sealant may be reduced by addition to the polyglycidyl ether. This is preferable because it is possible. Addition of a cycloaliphatic diepoxy compound as shown in 1,2,8,9-diepoxy limonene is also preferred. Since these compounds are integrated by copolymerizing with epoxy molecules at the time of the curing reaction, it is preferable because the physical properties of the cured product can be prevented from being reduced by blending and the volume at the time of curing can be prevented.

  The blending proportion of the alkylene diglycidyl ether compound is preferably 10 to 80% by weight, more preferably 50 to 80% by weight, based on the entire mixture. When it is less than 10% by weight, the effect of reducing the viscosity of the sealant is reduced, and the permeability of the sealant cannot be increased. On the other hand, if the amount exceeds 80% by weight, the permeability of the sealant increases, but the proportion of the triglycidyl ether compound, which plays a role in forming a high-density cross-linked structure at the time of curing, is relatively reduced. The physical properties of the epoxy resin are reduced.

  The alkylene diglycidyl ether compound is mixed with the above-mentioned triglycidyl ether compound in a predetermined amount, so that the substrate adhesion force, molecular cross-linking density, and resin hardness of the triglycidyl ether compound itself can be sealed without significantly decreasing. By ensuring the penetration of the treatment agent, a sufficient function as a sealing treatment agent for thermal spray coating can be exhibited.

A monoglycidyl ether compound having one epoxy group contained in one molecule can be bonded to a part of the resin through a monofunctional group. In addition, since it is a low-viscosity epoxy compound itself, the viscosity of the sealing agent can be lowered, and on the other hand, it can reduce the residual stress inside the cured resin and provide an effect of adjusting the curing rate. it can.
It is preferable that the compounding quantity of a monoglycidyl ether compound shall be 0-30 weight% with respect to the whole mixture.
When the amount of monoglycidyl ether compound added exceeds 30% by weight, the amount of volatilization increases, the amount of triglycidyl ether compound decreases relatively, the crosslinking density of the resin after curing is insufficient, and the physical properties are greatly reduced. It becomes difficult to form a cured product. Moreover, since the compounding quantity of a polyglycidyl ether compound also reduces, the adhesive force between a thermal spray coating and a base material becomes small.

A curing agent is blended with the mixture of the glycidyl ether compounds. As the curing agent, a known epoxy resin curing agent such as an acid anhydride and an aliphatic amine compound, an alicyclic amine compound, an aromatic amine compound, or an imidazole may be used alone or in combination. Can do.
Examples of acid anhydrides include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitate, glycerol trislimitate, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydro Phthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, succinic anhydride, dodecenyl succinic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylcyclohexene Examples thereof include dicarboxylic acid anhydrides and derivatives thereof.
Among these, an acid anhydride curing agent having a viscosity at 25 ° C. of 50 mPa · s or less is a suitable curing agent because the viscosity of the entire sealing agent system can be significantly reduced by addition.
It is preferable that the compounding quantity of an acid anhydride hardening | curing agent shall be 0.80-0.95 equivalent with respect to 1 equivalent of epoxy groups.

  A surfactant can be added to the sealing agent of the present invention as other materials. Particularly effective surfactants include fluorine-based surfactants and silicon-based surfactants, and it is particularly preferable to use known fluorine-based surfactants. In the present invention, known anionic, cationic, nonionic and amphoteric surfactants can be used. When a fluorine-based surfactant is added to the sealing agent of the present invention, it can be used alone or in admixture of two or more. Moreover, if it is an additive which improves the surface active effect and the osmosis | permeation effect, such as silicone oil, it can be used in the range which does not disturb the characteristic of invention.

  As the anionic surfactant, sulfonate, sulfate, carboxylate, phosphate, phosphonate, phosphate ester and the like can be used. As the cationic surfactant, a quaternary ammonium salt, an amino halogen salt, or the like can be used. As the nonionic surfactant, polyoxyethylene ester type, polyoxyethylene ether type, sorbitan ester type and the like can be used. As the amphoteric surfactant, imidazoline type, betaine type and the like can be used.

The sealing treatment method comprises applying the sealing treatment agent of the present invention to a thermal spray coating formed by a known thermal spraying method on a surface of a base metal such as steel with a metal, alloy, oxide ceramics, carbide cermet or the like. It is used to seal the pores of the thermal spray coating.
Al, Zn, Cr, Ni etc. as the metal used as the spray material, stainless steel etc. as the alloy, alumina, zirconia, titania etc. as the oxide ceramics, chromium carbide, tungsten carbide etc. as the carbide cermet, Each can be mentioned.
As the spraying method, for example, a plasma spraying method, a high-speed gas flame spraying method, or the like can be used. The film thickness of the thermal spray coating can be appropriately set according to the type of the thermal spray material and the use of the resulting thermal spray coating coating member, but usually when carbon steel is the base material and the thermal spray material is alumina, 20 ~ It is about 2000 μm, preferably about 50 to 1000 μm.

In the above sealing treatment method, the penetration and filling properties of the sealing agent depend on the particle boundary fusion structure forming the sprayed coating to be treated. It is desirable to select an optimum sealing agent suitable for the required characteristics of the later sprayed coating.
For example, the sealing agent of the present invention is preferably used for sealing treatment when the formed sprayed coating has a porosity of 10% or less. Further, the sealing agent of the present invention is used for sealing treatment when the porosity of a thermal spray coating formed by plasma spraying or high-speed gas flame spraying method using ceramic powder or carbide cermet as a thermal spraying material is 10% or less. It is preferable to use it. When these thermal spray coatings are subjected to a sealing treatment using the sealing agent of the present invention, a very excellent sealing effect is exhibited, and the sealing effect is confirmed even if the surface layer is removed by grinding, for example, about 200 μm. can do.
As described above, by using the sealing agent of the present invention, the pores (gap) of the sprayed coating are substantially completely filled with the resin obtained by polymerizing the epoxy group. The thermal spray coating covering member which has can be obtained.
Here, the pores (gap) of the sprayed coating are “substantially all filled” means that the layer formed by the sealing agent existing in the form of a coating on the surface of the sprayed coating (sealing agent) In the dye penetration test based on JIS H 8666, the outermost layer part (for example, about 0.2 mm thick from the surface) of the thermal spray coating including the cured product of the components contained in the material is removed by grinding and polishing. , Meaning no coloration.

The above-mentioned sealing treatment method allows the above-mentioned sealing agent to penetrate to the bottom of the thermal spray coating and improve the filling property, thereby filling the gaps between the particles with certainty, thereby ensuring the individual bonding force between the particles and the base. The adhesion force with the material is increased, and all the gaps between the boundaries between particles can be filled. For this reason, the penetration | invasion of environmental moisture and a foreign material in air | atmosphere is interrupted | blocked, and the fall of an insulation resistance value and a dielectric breakdown value can be suppressed, without reducing the intrinsic | native value of an oxide ceramic sprayed coating. Further, the obtained thermally sprayed coating after sealing does not have an exposed gap even when the surface is ground or polished.
Therefore, it can be used as a means for increasing the mechanical strength of the sprayed coating itself and the adhesion strength with the base material, a means for suppressing a decrease in electrical characteristics such as an insulation resistance value and a dielectric breakdown value, and the like.

  When the sealing treatment is performed using the sealing treatment agent of the present invention, the gap between the thermal spray coatings is substantially filled with the sealing treatment agent, and then the coating with the sealing treatment agent is performed so as to conceal the surface layer of the thermal spray coating. A film-like thin layer is formed. The coated member having a thin layer in the form of a coating can be used as it is, but in order to maintain the dimensional accuracy of the coated member, the surface of the sprayed coating is ground and ground using a grinding wheel, abrasive paper, non-woven buff, etc. This layer can be removed by polishing.

  The sealing treatment is preferably performed quickly on the sprayed coating after spraying. The thermal spray coating is a coating formed by fusing a large number of particles having a particle size distribution only at the interparticle surface layer. Since gaps are inevitably generated at the particle boundaries, it is often affected by environmental conditions such as moisture and foreign matter entering through the gaps at the grain boundaries immediately after the formation of the coating. Therefore, in order to prevent a decrease in the sealing efficiency, it is desirable to perform the sealing treatment of the sprayed coating as soon as possible after spraying.

The thermal spray coating member of the present invention is formed by spraying hard particles such as metal or ceramics and powder on the surface of a base material of a machine part composed of steel or the like to form a thermal spray coating, and then the sealing treatment agent of the present invention. Is a covering member obtained by performing a sealing process until the gap between the sprayed coating materials is substantially filled. Therefore, the obtained thermal spray coating member is coated with a thermal spray coating on which the mechanical strength and adhesion strength with the base material are enhanced and electrical characteristics such as insulation resistance value and dielectric breakdown value are improved. As a result, the machine parts can be completely shielded from the surrounding environment to prevent and protect water and foreign matter from entering.
Further, the dimensional accuracy of the covering member can be maintained by grinding and polishing the surface of the sprayed coating using a grinding wheel, polishing paper, non-woven cloth buff or the like.

The thermal spray coating member of the present invention can be suitably applied to the surface of a member constituting a bearing. As a bearing, it can be used for either a rolling bearing or a sliding bearing. In a rolling bearing, an inner ring having an inner ring rolling surface on an outer peripheral surface and an outer ring having an outer ring rolling surface on an inner peripheral surface are arranged concentrically, and a plurality of rolling bearings are provided between the inner ring rolling surface and the outer ring rolling surface. A moving object is arranged. Furthermore, it is comprised with the sealing member fixed to the holder | retainer and outer ring | wheel etc. which hold | maintain these rolling elements.
The thermal spray coating member of the present invention can be suitably used as a sealing agent for a ceramic thermal spray coating to be processed on the outer ring portion of rolling bearings such as deep groove ball bearings and cylindrical / conical roller bearings.
The bearing whose outer ring surface has been treated with the thermal spray coating member is fixed by being pressed into the housing while sliding the outer diameter surface of the outer ring. By providing the thermal spray coating member of the present invention, the thermal spray coating is strengthened by the action of the encapsulating resin, so that the risk of damage to the coating due to collision with the housing that can occur during press-fitting can be reduced.
Moreover, the thermal spray coating covering member of the present invention can also be used as a sliding surface of a slide bearing.

Examples 1 to 5 and Comparative Examples 1 to 4
The materials used in Table 1 are shown below.
(1) Glycidyl ether compound or cycloaliphatic diepoxy compound (1-1) Trimethylolpropane triglycidyl ether: manufactured by Nagase ChemteX Corporation, Denacol EX-321L, viscosity: 500 mPa · s (25 ° C.)
(1-2) Alkylene diglycidyl ether: manufactured by Japan Epoxy Resin Co., Ltd., YED216M, viscosity; 15 mPa · s (25 ° C.)
(1-3) Alkylene monoglycidyl ether: manufactured by Japan Epoxy Resin, YED111E, viscosity; 7 mPa · s (25 ° C.)
(1-4) Cycloaliphatic diepoxy compound: Daicel Chemical Industries, Celoxide 3000, viscosity; 10 mPa · s (25 ° C.)
(2) Hydroxyl-containing vinyl ether compound (2-1) Vinyl ether A: manufactured by Maruzen Petrochemical Co., Ltd., industrial chemicals, 2-hydroxyethyl vinyl ether, viscosity; 3 mPa · s (20 ° C.), boiling point 140 ° C.
(2-2) Vinyl ether B: manufactured by Maruzen Petrochemical Co., Ltd., industrial chemicals, 4-hydroxybutyl vinyl ether, viscosity; 5 mPa · s (20 ° C.), boiling point 187 ° C.
(2-3) Vinyl ether C: manufactured by Maruzen Petrochemical Co., Ltd., industrial chemicals, diethylene glycol monovinyl ether, viscosity; 5 mPa · s (20 ° C.), boiling point 208 ° C.
(3) Polymerizable vinyl group-containing solvent (3-1) Styrene monomer: manufactured by Wako Pure Chemical Industries, reagent, viscosity; 1 mPa · s (20 ° C), boiling point 145 ° C
(4) Curing agent, curing accelerator (4-1) Acid anhydride curing agent: manufactured by Dainippon Ink & Chemicals, Epicron B-570, viscosity; 40 mPa · s (25 ° C.)
(4-2) Imidazole-based curing accelerator: Shikoku Kasei Kogyo Co., Ltd., OR-2E4MZ

Each component shown in Table 1 was sufficiently stirred and mixed at room temperature, and left to stand for 30 minutes to remove bubbles in the mixed resin, thereby obtaining a sealing agent. The obtained sealing agent was evaluated by a weight reduction rate test after firing.
<Weight reduction test after firing>
The obtained sealing agent was sufficiently dried under conditions of 140 ° C. × 2 hours, and weighed about 2 g in a glass container (capacity: 3 ml) with no foreign matter adhered to obtain a weighed value before firing. Then, with the mouth of the glass container kept open, pre-fired at 80 ° C for 1 hour, then fired at 120 ° C for 2 hours, measured the weight after firing, set the weight after firing, and sealed according to the following formula The weight reduction rate of the treatment agent was measured. The measurement results are shown in Table 1. The criterion for the measurement results is that if the weight loss rate exceeds 1%, voids are generated after curing in the microscopic voids remaining in the sprayed coating, or the generation of residual bubbles in the cured product increases due to the generated gas. Therefore, 1% or less is judged as “possible”. Further, “uncured” is a case where the material did not become solid under the above-described firing conditions.

Weight reduction rate after firing (%) = 100 × (weighed value before firing−weighed value after firing) / weighed value before firing

Next, a φ20 mm × 25 mm SUJ2 test piece (hereinafter referred to as “test piece base material”) was prepared, and an alumina ceramic sprayed coating having a film thickness of 400 μm was formed on the cylindrical end face by an atmospheric plasma spraying method.
On the surface of the sprayed surface, the sealing agent shown in Table 1 was applied using a polyamide brush in a room temperature atmosphere and allowed to stand for 30 minutes. Thereafter, a test piece coated with a sealing agent was prepared by scraping off the excess sealing agent on the surface with a polyethylene spatula. Thereafter, these coated test pieces were pre-fired at 80 ° C. for 1 hour, and then fired at 120 ° C. for 2 hours to cure the sealing agent. Next, grinding removal was performed using a diamond grindstone parallel to the ceramic plane. The grinding removal amount was set at the following three levels.
(1) The ceramic part was ground and removed by about 10 μm for the purpose of intensively removing the cured resin layer on the surface layer part.
(2) About 200 μm was ground and removed for the purpose of removing the resin permeation layer from the surface of the cured specimen to a depth of about 200 μm.
(3) About 400 μm was removed by grinding for the purpose of removing the resin permeation layer from the surface of the cured test piece to a depth of about 400 μm.
Measure the permeability, adhesion, insulation resistance, and withstand voltage characteristics with the following permeability test, adhesion test, insulation resistance test, and withstand voltage test using the cured specimen obtained by grinding and removing the surface. did. In addition, a test for confirming whether low-temperature firing was possible was performed.

<Penetration test>
The permeability test of the cured test piece was performed by applying a ferroxyl test based on JIS H 8666 to the coating surface of the cured test piece subjected to the sealing treatment. An outline of the ferroxyl test is shown in FIG. The test conditions were the test solution composition, test surface, except that the shape of the filter paper 3, tin plate 4 and weight 5 in which the test solution shown in FIG. 1 was immersed was adjusted to the test piece (φ16 mm). All conditions such as pressure and standing time were in accordance with JIS H 8666. When the filter paper 3 is colored, the sprayed coating 2 has a communication hole that connects the test piece base 1 and the external space, so that the ferroxyl test solution contacts the iron ions of the test piece base 1 and turns blue. Indicates that Judgment criteria are “spotted” when one or more blue spots were seen on the surface of filter paper 3 that was originally white, and “no spots” when zero blue spots were found, The permeability measurement results are also shown in Table 1.

<Adhesion test>
An outline of the adhesion test is shown in FIG. Tensile jig 6 (adhesive part shape: φ16 mm) is bonded to epoxy test surface 2a via a high-viscosity epoxy adhesive to the cured test piece with the surface layer portion after firing removed by 200μm. The adhesion of the thermal spray coating 2 per unit area was measured by pulling in the direction of the arrow with a machine. The measurement results are also shown in Table 1. Judgment criteria are “possible” when the adhesion is 2 MPa or more, and “impossible” when it is below 2 MPa.

<Insulation resistance test>
An outline of the insulation resistance test is shown in FIG. After immersing the cured test piece in warm water at 80 ° C. for 1 hour, the insulation resistance between the surface of the sprayed coating 2 and the test piece base 1 was measured using a 1000 V DC insulation resistance meter 8 attached to the wiring 9. 7 is an electrode. The measurement results are also shown in Table 1. The judgment criterion is “OK” when the resistivity exceeds 2000 MΩ (indicated as> 2000 in the table), and “No” when the resistivity is lower than 2000 MΩ.

<Withstand voltage characteristics test>
An outline of the withstand voltage characteristic test is shown in FIG. A voltage of DC 5 kV was applied by a high voltage generator 10 attached to the wiring 9 between the thermal spray coating 2 and the test piece base 1, and the withstand voltage characteristics were evaluated by the monitor 11. 7 is an electrode. The measurement results are also shown in Table 1. The judgment criteria were DC 5 kV applied for 5 minutes, "No" if no dielectric breakdown occurred, and "No" if dielectric breakdown occurred.

<Low temperature firing possibility confirmation test>
The normal firing conditions are 80 ° C x 1 hour for pre-baking and then 120 ° C x 2 hours for main firing, but for the purpose of suppressing productivity during mass production and heat distortion of products subjected to sealing treatment. There is a demand to relax firing conditions. Therefore, the main firing was performed under conditions of 100 ° C. × 2 hours, which is a milder condition than usual, and the feasibility of low-temperature firing of the sealing agent composition was confirmed by comparing with the normal fired product. The comparative item was <withstand voltage characteristic>, and the outline of the withstand voltage characteristic test was performed in the same manner as in the above <withstand voltage characteristic test>. The experimental results are also shown in Table 1. As with the result of the withstand voltage characteristic test of the normal fired product, the determination criterion was “appropriate” when DC 5 kV was applied for 5 minutes and no dielectric breakdown occurred, and “impossible” when dielectric breakdown occurred.

As shown in Table 1, the sealing agent of each example had a weight reduction rate of less than 1%, and the weight reduction after firing was lower than that of the addition system of the alkylene monoepoxy compound shown in Comparative Example 1. became. Thereby, by using this composition, a more reliable sealing property than the conventional composition can be expected.
In Examples 1, 2, 3, 4, and 5, since the extremely low viscosity hydroxyl group-containing vinyl ether compound was used, the viscosity of the sealing agent itself could be remarkably lowered, so that the sealing agent could penetrate to a depth of 400 μm. It became.
In Comparative Example 1, an alkylene monoepoxy compound was used as a diluting solvent. As a result, the composition of the sealing agent excluding the curing agent was almost entirely composed of the epoxy compound. In contrast, Examples 1, 2, 3, 4, and 5 employ a hydroxyl group-containing vinyl ether compound as a diluent solvent, which not only lowers the viscosity of the system, but also promotes the ring opening reaction of the epoxy group due to the presence of the hydroxyl group. As a result, low-temperature firing became possible. When an acid anhydride is used as a curing agent, the curing reaction rate is slow as it is, so it is generally necessary to use a curing accelerator such as amine or imidazole. However, amines are highly toxic and irritating. Since many imidazoles have high viscosity and poor dispersibility, there is a demand to reduce the use of these curing accelerators as much as possible. However, the combined use of vinyl ether additives can reduce the amount of these curing accelerators used.
Comparative Example 2 uses a styrene monomer that has a relatively large amount of evaporation during firing as a diluent solvent, so the evaporation loss is large, and the withstand voltage characteristics are less than the acceptance criteria at the stage where 200 μm is ground and removed from the surface of the sprayed coating. became.
In any of Comparative Examples 3 and 4, it is considered that the amount of the hydroxyl group-containing vinyl ether added as a diluent solvent was insufficient or excessive. In Comparative Example 3, since the amount of vinyl ether added was small, the effect of reducing the viscosity of the sealing agent was low. As a result, there was no problem up to a grinding amount of 200 μm, but the permeability was insufficient at a grinding amount of 400 μm. Moreover, since the amount of hydroxyl groups showing a curing accelerating effect was small, low-temperature firing became impossible. On the other hand, in Comparative Example 4, since the addition amount of the hydroxyl group-containing vinyl ether was too large, the epoxy component constituting the main skeleton of the resin after curing was insufficient, and the adhesion and strength of the cured product were significantly reduced. As a result, a gap between the filled resin and the film was generated due to the processing impact during grinding from the level of grinding of 200 μm or more, and the electrical characteristics deteriorated due to moisture entering the gap.
From the above results, it can be said that the addition of a predetermined amount of a hydroxyl group-containing vinyl ether is a very effective means as an additive for a sealing agent in the present invention.

  The above test results are that the pores (gap) of the thermal spray coating is filled with the sealing agent of the present invention, thereby improving the adhesion between the substrate and the thermal spray coating, and further preventing the intrusion of moisture in the atmosphere, It shows that the decrease in the insulation resistance value and the withstand voltage characteristic can be suppressed without reducing the intrinsic value of the oxide ceramic sprayed coating.

  By using the sealing agent of the present invention, the sealing treatment can be performed until the pores (gap) are excellent in permeability and filling property and substantially all the gaps of the thermal spray coating material are filled. For this reason, there is no possibility that the sealing characteristics with time will be deteriorated, and it can be suitably used as a sealing agent for forming a sprayed coating without peeling during use.

  In addition, since the spray coating member of the present invention has a sufficient penetration / filling layer of the sealing agent, even if the surface layer portion of the spray coating is ground or polished after the sealing treatment, the heat resistance and wear resistance of the spray coating are reduced. Property and corrosion resistance can be greatly improved, and further physical properties such as mechanical properties and electrical properties can be improved. For this reason, it can utilize suitably as a member for protection of a thermal-sprayed film of various industrial machine parts comprised from steel etc. which require high-precision post-processing, and a modification member. Especially applicable to insulated bearings.

It is a figure which shows the outline of a ferroxyl test. It is a figure which shows the outline of an adhesive force test. It is a figure which shows the outline of an insulation resistance test. It is a figure which shows the outline of a withstand voltage characteristic test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Test piece base material 2 Sealed thermal spray coating 3 Filter paper with ferroxyl test solution 4 Tin plate 5 Weight 6 Tension jig 7 Electrode 8 Insulation resistance meter 9 Wiring 10 High voltage generator 11 Monitor

Claims (5)

A thermal spray coating sealing agent comprising an epoxy group-containing component, a curing agent for the epoxy group-containing component, and a hydroxyl group-containing vinyl ether compound, and no polymerizable vinyl group-containing solvent other than the hydroxyl group-containing vinyl ether compound. And
The said hydroxyl-containing vinyl ether compound is mix | blended 10 to 30weight% with respect to the whole said epoxy-group containing component, The sealing agent characterized by the above-mentioned.   The epoxy group-containing component includes a polyglycidyl ether compound having 3 or more epoxy groups contained in one molecule as an essential component, and an alkylene diglycidyl ether compound having 2 epoxy groups contained in one molecule. And a polyglycidyl ether compound in an amount of 10 to 80% by weight based on the entire epoxy group-containing component excluding the curing agent. The sealing agent according to claim 1.   The sealing agent according to claim 2, wherein the epoxy group-containing component further comprises a monoglycidyl ether compound having one epoxy group in one molecule.   A thermal spray coating member having a thermal spray coating that has been sealed with a sealing agent on a metal substrate, wherein the sealing agent is the sealing agent according to claim 1, claim 2, or claim 3. A thermal spray coating member characterized by the above.   The bearing in which the thermal spray coating member is formed on the surface of the bearing constituent member, wherein the thermal spray coating member is the thermal spray coating member according to claim 4.

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