JP2012219183A - Coating composition, coating film composition and elastomer-coated gasket, and method for preventing fixing of gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition that effectively and efficiently prevents fixing of an elastomer component, for example, of a gasket coated with an elastomer to a counter member without detriment to inherent sealability of the gasket, a coating film composition, an elastomer-coated gasket coated with the coating composition, and a method for preventing fixing of the gasket.SOLUTION: A coating composition containing at least an anionic polyester-based urethane resin, a solid lubricating agent and a solvent, with the content of the anionic polyester-based urethane resin of at least 9 mass% and at most 15 mass% and the content of the solid lubricating agent of at least 85 mass% and at most 91 mass%, each based on 100 mass% of the solid contents, is applied on an elastomer-coated layer of a gasket coated with the elastomer.

Description

  The present invention relates to a coating composition and a coating composition, and in particular, for example, a coating composition suitable for use in preventing adhesion of a gasket coated with an elastomer, a coating composition, and an elastomer coating on which the coating composition is applied. The present invention relates to a gasket and a method for preventing adhesion of the gasket.

  Conventionally, it is known that a metal gasket is coated with an elastomer such as acrylonitrile butadiene rubber (NBR), for example, in order to improve adhesion to a counterpart material such as a cylinder.

  For example, Patent Document 1 proposes a method of making a rubber-coated stainless steel sheet for gaskets excellent in microsealability by coating NBR with a ketone solvent. Patent Document 2 discloses an epoxy resin-coated iron alloy in which a cured coating film of an epoxy resin coating in which talc, clay, molybdenum disulfide, silica, calcium carbonate, mica, alumina, and the like are blended is formed on the surface of an iron alloy body. The body has been proposed. In Patent Document 3, a non-adhesive treatment layer is formed by applying a non-adhesive treatment coating composition comprising a fluororesin, a fluororubber, a vulcanizing agent, and a liquid carrier on a rubber layer. The body has been proposed.

  However, the technique described in Patent Document 1 relates to an efficient manufacturing method by a continuous coating method of a gasket having characteristics as a micro seal film. Although NBR alone can provide micro seal characteristics, NBR is When softened at a high temperature, there arises a problem that the gasket adheres to the mating material.

  Moreover, in the technique described in Patent Document 2, the use of an epoxy resin paint made of an epoxy resin containing an inorganic fine body improves the applicability to an iron alloy body, but the epoxy resin has insufficient flexibility. Therefore, the original adhesiveness of the gasket is impaired, and there is no way of thinking about preventing sticking to the counterpart material.

  As described above, in the techniques described in Patent Documents 1 and 2, for example, when used in a high temperature environment such as an engine part of an automobile, the elastomer coated on the gasket is softened by the high temperature and is fixed to the counterpart material. There's a problem.

  In this regard, the technique described in Patent Document 3 describes that fluoro rubber is used to prevent sticking of the rubber layer without impairing the original sealing property of the rubber. However, the fluororubber used in this technique is an expensive material, and it is not possible to efficiently prevent the elastomer component coated on the gasket from adhering to the counterpart material.

  As described above, the conventional techniques have not been able to effectively and efficiently prevent sticking to the counterpart material due to softening of the elastomer coated on the gasket without impairing the original sealing performance of the gasket.

Japanese Patent No. 2663320 Japanese Patent No. 3737569 JP 2009-190171 A

  Therefore, the present invention has been proposed in view of the above-described circumstances. For example, in an elastomer-coated gasket, the elastomer component can be effectively fixed to a mating member without impairing the original sealing performance of the gasket. It is another object of the present invention to provide a coating composition, a coating composition, an elastomer-coated gasket to which the coating composition is applied, and a method for preventing adhesion of the gasket, which can be efficiently prevented.

  As a result of extensive research, the present inventors applied a coating composition containing a predetermined amount of an anionic polyester-based water-based urethane resin and a solid lubricant to a coating layer of a gasket coated with an elastomer. Thus, it has been found that the elastomer component coated on the gasket can be prevented from adhering to the counterpart material without impairing the original sealing property of the gasket, and the present invention has been completed.

  That is, the coating composition according to the present invention contains at least an anionic polyester urethane resin, a solid lubricant, and a solvent, and the anionic polyester in the solid content (100% by mass) of the coating composition. A urethane resin is contained in a proportion of 9% by mass to 15% by mass and the solid lubricant is contained in a proportion of 85% by mass to 91% by mass.

  Moreover, the coating-film composition which concerns on this invention contains 9 mass% or more and 15 mass% or less anionic polyester-type urethane resin in solid content, and 85 to 91 mass% solid lubricant. Become.

  The elastomer-coated gasket according to the present invention contains at least an anionic polyester-based urethane resin, a solid lubricant, and a solvent, and the anionic polyester-based urethane resin in the solid content (100% by mass) is 9%. A coating composition containing at least 15% by mass and not more than 15% by mass and at least 85% by mass and not more than 91% by mass of the solid lubricant is applied on the elastomer coating layer.

  Further, the gasket sticking prevention method according to the present invention is a gasket sticking prevention method for preventing the elastomer from sticking to a mating material of the gasket coated with the elastomer, and at least an anion on the elastomer coating layer of the gasket. The anionic polyester urethane resin is contained in an amount of 9% by mass to 15% by mass and the solid lubricant is 85% in a solid content (100% by mass). A coating composition containing from mass% to 91 mass% is applied.

  According to the present invention, for example, in a gasket or the like coated with an elastomer such as NBR, it is possible to prevent the elastomer component from adhering to the counterpart material without imparting high adhesion and deteriorating its original sealing property. .

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail. In the present embodiment, the case where the coating composition according to the present invention is applied to an elastomer surface in a gasket coated with an elastomer will be described as an example.

  The coating composition according to the present embodiment contains at least an anionic polyester urethane resin, a solid lubricant, and a solvent. And this coating composition contains 9 mass% or more and 15 mass% or less of anionic polyester-type urethane resin in solid content (100 mass%) of a coating composition, and 85 mass% of solid lubricants. The content is 91% by mass or less.

  And the coating-film composition formed by apply | coating this coating composition is 9 mass% or more and 15 mass% or less anionic polyester type urethane resin in solid content, and 85 mass% or more and 91 mass% or less. It contains a solid lubricant.

  According to such a coating composition and a coating film composition, a predetermined amount of an anionic polyester-based urethane resin is contained, thereby providing the coating film composition with high flexibility, and a gasket, an elastomer, High adhesion can be imparted between them, and the original sealing function of the gasket and elastomer can be maintained. Moreover, even when the elastomer coated on the gasket is softened at a high temperature by containing a solid lubricant at a high concentration with respect to the anionic polyester urethane resin, the coating composition is the counterpart of the gasket. Adhering to a material (for example, a washer) is efficiently and effectively prevented.

  The anionic polyester urethane resin is not particularly limited as long as it has good adhesion to rubber or plastic, but for example, adhesion to acrylonitrile butadiene rubber (NBR) is a cross-cut method (JIS K 5600-5-6: 1 or less in the evaluation classification according to 1 mm) is preferable. Thereby, high adhesiveness can be provided more effectively between the gasket and the elastomer.

  As described above, the content of the anionic polyester urethane resin is 9% by mass to 15% by mass in the solid content (100% by mass) of the coating composition. By setting the content to 9% by mass or more, it is possible to prevent surface peeling of the formed coating film, and to sufficiently exhibit its high flexibility effect, and to inherently seal the gasket coated with elastomer. Can be maintained. Moreover, by setting the content to 15% by mass or less, it is possible to effectively prevent the elastomer component coated on the gasket from adhering to the counterpart material without impairing the original sealing performance of the gasket.

  The blending amount of the anionic polyester-based urethane resin with respect to the total mass of the coating composition is not particularly limited as long as it is prepared so that the content in the solid content of the coating composition is in the above-described range. The ratio is 25% by mass or less.

  The solid lubricant is not particularly limited, and examples thereof include molybdenum disulfide, graphite, and polytetrafluoroethylene. In particular, molybdenum disulfide is more suitable for high loads, and polytetrafluoroethylene is more preferable from the viewpoint of excellent slipperiness and a low friction coefficient. The average particle size of the solid lubricant to be used is not particularly limited, but it is preferably 10 μm or less for molybdenum disulfide, 10 μm or less for graphite, and 10 μm or less for polytetrafluoroethylene.

  These solid lubricants can be used alone or in combination of two or more. In particular, by using a solid lubricant in which the above-described molybdenum disulfide and polytetrafluoroethylene are mixed and blended, the elastomer component can be more effectively prevented from sticking.

  As described above, the content of the solid lubricant is 85% by mass to 91% by mass in the solid content (100% by mass) of the coating composition. By setting the content to 85% by mass or more, it is possible to effectively prevent the elastomer component coated on the gasket from adhering to the counterpart material. Further, by setting the content to 91% by mass or less, the elastomer can be effectively prevented from sticking without impairing the original adhesion of the gasket. Thus, by adhering the solid lubricant at a high concentration to the water-based urethane resin, it is possible to effectively prevent the gasket from adhering to the counterpart material due to high-temperature softening of the elastomer component.

  The blending amount of the solid lubricant with respect to the total mass of the coating composition is not particularly limited as long as it is adjusted so that the content in the solid content of the coating composition is in the above-described range. % Or less.

  The solvent is used to dissolve or disperse the above-described anionic polyester urethane resin and solid lubricant. Although it does not restrict | limit especially as this solvent, Water and various organic solvents can be used. Among these, it is preferable to use water as a solvent from the viewpoint of safe and efficient production and use. Alternatively, it is preferable to use an organic solvent such as polyethylene glycol, ethylene glycol, or propylene glycol from the viewpoint that it has a property that is less volatile than water and can improve operability during coating.

  The solvent mentioned above can be used individually by 1 type or in mixture of 2 or more types. In particular, when two or more kinds are mixed and used, it is preferable to use a mixed solvent of water and an organic solvent selected from the above-described polyethylene glycol, ethylene glycol, propylene glycol and the like.

  The blending amount of the solvent with respect to the total mass of the coating composition varies depending on the amount of components to be dissolved or dispersed, but is, for example, a ratio of 17% by mass to 27% by mass.

  The coating composition in the present embodiment can contain various additives as necessary in addition to the above-described anionic polyethylene urethane resin, solid lubricant, and solvent. Examples of additives that can be added as necessary include extreme pressure agents, colorants, surfactants, dispersants, antioxidants, flame retardants, antistatic agents, leveling agents, antifoaming agents, and silane coupling agents. Can be mentioned. However, it is assumed that the required performance is not deteriorated by blending these additives.

  As described above, the coating composition according to the present embodiment contains at least an anionic polyester urethane resin, a solid lubricant, and a solvent, and in the solid content (100% by mass) of the coating composition, An anionic polyester urethane resin is contained in an amount of 5% by mass to 9% by mass and a solid lubricant is contained in an amount of 86% by mass to 91% by mass. As a result, the coating composition is applied to the surface of the elastomer (coating layer) on the gasket coated with the elastomer, so that the elastomer is softened at a high temperature so that it is fixed to the mating material of the gasket, such as a washer. It can be effectively suppressed. Therefore, it can be suitably used especially for a gasket used in a high temperature environment such as an engine part of an automobile, effectively preventing the gasket from adhering to the mating member during maintenance, etc. Work can be performed efficiently.

  Here, when the coating composition described above is applied to the surface of the elastomer coating layer, the anionic polyester urethane resin having a solid content of 9% by mass to 15% by mass and 85% by mass or more is present on the surface. A coating composition comprising 91% by mass or less of a solid lubricant is formed.

  The elastomer to which the above-described coating composition can be applied is not particularly limited, and can be applied to known elastomers such as nitrile rubber, hydrogenated nitrile rubber, silicone rubber, and fluororubber. Further, the elastomer may be formed by blending a filler such as carbon black, silica, charcoal calcelite, an anti-aging agent, a processing aid, a vulcanizing agent, etc. with respect to the main raw material described above. .

  In addition, the method of applying the above-described coating composition to a coating film formation target such as an elastomer is not particularly limited, and examples thereof include spray coating, dip coating, brush coating, flow coating, dispenser coating, and screen coating. It is done. In addition, before apply | coating to the surface etc. of an elastomer, it is preferable to fully degrease and wash | clean the surface.

  Thus, in an elastomer-coated gasket in which a coating composition containing a solid lubricant at a high concentration relative to an anionic polyester urethane resin is formed on the surface of an elastomer, even when the elastomer component is softened at a high temperature The gasket can be prevented from sticking to the mating material. Moreover, since the formed coating film composition contains an anionic polyester urethane resin in a proportion of 9% by mass or more and 15% by mass or less, high adhesion to the gasket can be imparted, The elastomer can be effectively prevented from sticking without impairing the original adhesion of the gasket.

  In the above description, the mode in which the coating composition is mainly applied to the elastomer has been described as an example. However, the application target is not limited to the elastomer. The present invention can be applied to a base material provided with. For example, it is also suitable for use on base materials such as general-purpose resins such as polypropylene, polyoxymethylene, polyimide, polyamideimide, polysulfone, polyethersulfone, polyetheretherketone, and heat-resistant resins. Can do.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

<Evaluation of adhesion>
First, the paint (Example 1, Comparative Examples 1-3) produced as follows was applied to a test piece (end material of gasket packing) using a sponge roller to form a coating film. The adhesion of the coating film was evaluated. The adhesion evaluation was evaluated by setting the clearance of the cutter guide to 1 mm based on JIS K 5600-5-6 adhesion (cross-cut method).

Example 1
In Example 1, 5.9% by mass of water and 16.3% by mass of propylene glycol as a solvent were blended with 31.0% by mass of molybdenum disulfide, which is a solid lubricant, and 21.5% by mass of polytetrafluoroethylene. Further, 3.9% by mass of an additive was added, and steel beads were added in the same volume as the total amount of each component, and stirred for 30 minutes with a high-speed disper (DISPERMAT AE, VMA-GETZMANN GmbH).

  Subsequently, after removing the steel beads by filtration, an anionic polyester urethane resin (Superflex 210, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), which is a water-based urethane resin, 21.4% by mass (solid content 7.5% by mass) Was mixed for 10 minutes with a high-speed disper to prepare a paint.

  In the solid content (100% by mass) of the obtained coating material, the solid content of the anionic polyester urethane resin is 12.5% by mass, molybdenum disulfide is 51.7% by mass, and polytetrafluoroethylene is 35.8% by mass. It was contained in the ratio. The mass ratio of the solid lubricant to the anionic polyurethane resin was 7: 1.

(Comparative Example 1)
In Comparative Example 1, an anionic carbonate urethane resin (Superflex 410, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 18.7% by mass (solid content 7.5% by mass) was added as the water-based urethane resin. A paint was prepared in the same manner as in Example 1. The weight loss of the water-based urethane resin was prepared with water. The content ratio of the water-based urethane resin, molybdenum disulfide, and polytetrafluoroethylene in the solid content (100% by mass) of the obtained paint was the same as that in Example 1.

(Comparative Example 2)
In Comparative Example 2, a nonionic polyester urethane resin (Bondick 2220, manufactured by DIC Corporation) 18.8% by mass (solid content 7.5% by mass) was added as the water-based urethane resin. A paint was prepared in the same manner as in 1. The weight loss of the water-based urethane resin was prepared with water. The content ratio of the water-based urethane resin, molybdenum disulfide, and polytetrafluoroethylene in the solid content (100% by mass) of the obtained paint was the same as that in Example 1.

(Comparative Example 3)
In Comparative Example 3, a cationic ether urethane resin (Superflex 600, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 30.0% by mass (solid content 7.5% by mass) was added as an aqueous urethane resin. A paint was prepared in the same manner as in Example 1. The weight loss of the water-based urethane resin was prepared with water. The content ratio of the water-based urethane resin, molybdenum disulfide, and polytetrafluoroethylene in the solid content (100% by mass) of the obtained paint was the same as that in Example 1.

  In Table 1, the coating composition formed by apply | coating the coating material created in Example 1 and Comparative Examples 1-3 and the evaluation result of the adhesive evaluation of the coating composition are shown. In addition, adhesive evaluation was performed by 6 steps | paragraphs of classification | category 0-5 based on evaluation of JISK5600-5-6 adhesiveness (cross-cut method).

  As shown in Table 1, in Example 1 using an anionic polyester-based urethane resin, it was evaluated as category 0 without peeling at all, and it was shown that there was high adhesion. On the other hand, in Comparative Examples 1 to 3 using other water-based urethane resins, peeling occurred, which was evaluated as classification 5, and it was shown that adhesion could not be obtained.

<Evaluation of adhesion>
Next, a coating film was formed on the surface of the NBR using the coating material prepared in Example 1 and the coating material prepared as described below (Examples 2 and 3, Comparative Examples 4 and 5), and the NBR washer. The state of sticking was investigated. For the stickiness evaluation, paint was applied to the surface of the NBR with a bolt hole using a sponge roller, pinched with a washer, the bolt was tightened with a specified tightening force, left at 200 ° C for 1 hour, and after cooling, the washer was The NBR was fixed to the washer. In addition, the adhesion was also evaluated based on JIS K 5600-5-6 adhesion (cross-cut method: 1 mm).

(Example 2)
In Example 2, 24.5% by mass (solid content: 8.6% by mass) of anionic polyester urethane resin, which is a water-based urethane resin, 30.4% by mass of molybdenum disulfide, and 21.0% of polytetrafluoroethylene A coating material was produced in the same manner as in Example 1 except that it was blended at a ratio of mass%.

  In the solid content (100% by mass) of the obtained coating material, the solid content of the anionic polyester urethane resin is 14.3% by mass, 50.7% by mass of molybdenum disulfide, and 35.0% by mass of polytetrafluoroethylene. It was contained in the ratio. The mass ratio of the solid lubricant to the anionic polyurethane resin was 6: 1.

(Example 3)
In Example 3, 15.6% by mass (solid content 5.5% by mass) of anionic polyester urethane resin, which is a water-based urethane resin, 32.3% by mass of molybdenum disulfide, and 22.3 of polytetrafluoroethylene. A coating material was produced in the same manner as in Example 1 except that it was blended at a ratio of mass%.

  In the solid content (100% by mass) of the obtained coating material, the solid content of the anionic polyester urethane resin is 9.1% by mass, molybdenum disulfide is 53.7% by mass, and polytetrafluoroethylene is 37.2% by mass. It was contained in the ratio. The mass ratio of the solid lubricant to the anionic polyurethane resin was 10: 1.

(Comparative Example 4)
In Comparative Example 4, 28.6 mass% (solid content 10.0 mass%) of an anionic polyester urethane resin which is a water-based urethane resin, 29.5 mass% of molybdenum disulfide, and 20.5 mass of polytetrafluoroethylene A coating material was produced in the same manner as in Example 1 except that it was blended at a ratio of mass%.

  In the solid content (100% by mass) of the obtained coating material, the solid content of the anionic polyester urethane resin is 16.6% by mass, molybdenum disulfide is 49.2% by mass, and polytetrafluoroethylene is 34.2% by mass. It was contained in the ratio. The mass ratio between the solid lubricant and the anionic polyurethane resin was 5: 1.

(Comparative Example 5)
In Comparative Example 5, 34.3% by mass (solid content: 12.0% by mass) of anionic polyester urethane resin, which is a water-based urethane resin, 28.3% by mass of molybdenum disulfide, and 19.7% of polytetrafluoroethylene A coating material was produced in the same manner as in Example 1 except that it was blended at a ratio of mass%.

  In the solid content (100% by mass) of the obtained paint, the solid content of the anionic polyester urethane resin is 20.0% by mass, molybdenum disulfide is 47.2% by mass, and polytetrafluoroethylene is 32.8% by mass. It was contained in the ratio. The mass ratio of solid lubricant to anionic polyurethane resin was 4: 1.

  Table 2 shows the coating compositions formed by applying the coating materials prepared in Examples 1 to 3 and Comparative Examples 4 and 5 and the test results of the stickiness evaluation and adhesion evaluation of the coating compositions.

  As shown in Table 2, in the solid content (100% by mass), the anionic polyester urethane resin is 9% by mass to 15% by mass and the solid lubricant is contained in a proportion of 85% by mass to 91% by mass. In Examples 1 to 3 in which the coating composition was formed, NBR was not fixed to the washer. Also, the adhesion was evaluated as classification 0 in Examples 1 and 2 and classification 1 in Example 3, and high adhesion could be obtained.

  On the other hand, in the solid content (100% by mass), an anionic polyester urethane resin was 16.6% by mass, and a coating composition containing a solid lubricant in a proportion of 83.4% by mass was formed. In Comparative Example 4, although high adhesion was obtained, about 5% NBR fixation was recognized. In Comparative Example 5 in which a coating composition containing 20.0% by weight of an anionic polyester urethane resin and 80.0% by weight of a solid lubricant was formed, NBR of about 10% was formed. Was confirmed.

  From the above results, at least an anionic polyester urethane resin, a solid lubricant, and a solvent are contained, and the anionic polyester urethane resin is contained in an amount of 9% by mass to 15% by mass in the solid content (100% by mass). Hereinafter, by applying a coating composition containing a solid lubricant in a proportion of 85% by mass or more and 91% by mass or less to the surface of an elastomer such as NBR coated on a gasket, high adhesion is imparted. Thus, it has been found that the elastomer component can be effectively and efficiently prevented from sticking to the mating material of the gasket without impairing the original sealing performance of the gasket.

Claims (8)

  It contains at least 9% by mass to 15% by mass of the anionic polyester type urethane resin in the solid content (100% by mass) of the coating composition containing at least an anionic polyester type urethane resin, a solid lubricant, and a solvent. Hereinafter, a coating composition comprising the solid lubricant in a proportion of 85% by mass to 91% by mass.   2. The coating composition according to claim 1, wherein the solid lubricant is at least one selected from molybdenum disulfide, graphite, and polytetrafluoroethylene.   3. The coating composition according to claim 1 or 2, wherein the coating composition is applied on the elastomer coating layer of the gasket coated with an elastomer and is used for preventing adhesion of the elastomer to the mating material of the gasket.   A coating composition comprising 9% by mass to 15% by mass of an anionic polyester urethane resin and 85% by mass to 91% by mass of a solid lubricant in a solid content.   5. The coating composition according to claim 4, wherein the solid lubricant is at least one selected from molybdenum disulfide, graphite, and polytetrafluoroethylene.   6. The coating composition according to claim 4 or 5, which is coated on the elastomer coating layer of the gasket coated with an elastomer.   At least an anionic polyester-based urethane resin, a solid lubricant, and a solvent are contained, and in the solid content (100% by mass), the anionic polyester-based urethane resin is contained in an amount of 9% by mass to 15% by mass. An elastomer-coated gasket in which a coating composition containing an agent in a proportion of 85% by mass to 91% by mass is applied on an elastomer coating layer. A method for preventing adhesion of a gasket for preventing adhesion of the elastomer to a mating material of a gasket coated with an elastomer,
The elastomer coating layer of the gasket contains at least an anionic polyester urethane resin, a solid lubricant, and a solvent, and the anionic polyester urethane resin is 9% by mass in the solid content (100% by mass). A method for preventing adhesion of a gasket, comprising applying a coating composition comprising 15% by mass or less and the solid lubricant in a proportion of 85% by mass to 91% by mass.