JP4340489B2 - COATING WITH DAMAGE RESISTANT COATING, DAMAGE RESISTANT COATING, AND METHOD FOR PRODUCING DAMAGE RESISTANT COATING - Google Patents

Description

  The present invention relates to a coating in which a damage resistant coating is formed on the surface of various materials, a damage resistant coating, and a method for producing the damage resistant coating.

  As a method of imparting corrosion resistance to the surface of materials such as carbon steel, which is a machine part or fastening member, to prevent deterioration due to friction, moisture, etc., coating of inorganic paint on the material surface and metal plating of zinc or the like is generally well used. Are known. However, these methods have problems such as poor corrosion resistance against chemicals.

  As a means for solving this, a method of coating a fluororesin excellent in long-term corrosion resistance is often used. Fluororesin has a small coefficient of friction and exhibits good friction characteristics, so that it is often used in fastening members such as bolts and nuts since it has a low covering torque or tightening torque. However, in the method of coating the fluororesin, the coating is soft and weak, so when applied to a sliding material, a fastening member, etc., the coating applied to the surface of a metal material or the like is liable to be damaged and severe sliding (friction ) There is a problem that wear becomes severe under conditions.

As a method for solving the above problem, a method of adding fibrillated aramid fibers to a fluororesin has been proposed (see Patent Document 1). In addition, a sliding layer is made of a resin containing a fluororesin to ensure peeling resistance even under severe friction conditions, and a polyimide resin and / or a polyamideimide resin and fluorine are formed at the interface between the material surface and the sliding layer. A method of forming a two-layer structure provided with a resin bonding layer made of resin has been proposed (see Patent Document 2).
JP-A-6-122785 JP 2002-276665 A

  However, in Patent Document 1 and Patent Document 2, although the damage resistance of the fluororesin coating is improved by the fibrillated aramid fiber or the like, the essential problem that the coating is easily damaged has been sufficiently solved. Absent. Further, in Patent Document 2, although the destruction / peeling of the coating at the interface between the material surface and the coating is improved, there is also a problem that the manufacturing cost increases because the coating has a double structure.

  In this way, it has long-term corrosion resistance that can withstand chemicals, etc., has good lubricity, excellent damage resistance against sliding, and has ductility that does not cause destruction of the coating due to shearing. No coating has been developed that satisfies all the requirements of good mechanical properties such as strong impact resistance and resistance to breakage of the coating, and a coating more suitable as a mechanical part such as a sliding material or a fastening member has not been developed. is needed. Moreover, the coating which can be put into practical use for these uses is required to be able to thin the coating film formed on the material surface.

  Accordingly, the present invention solves the above-mentioned problems in view of such a background, has good mechanical properties such as long-term corrosion resistance, ductility, lubricity and impact resistance, and damage resistance having damage resistance against sliding. It is an object of the present invention to provide a coating on which a film is formed, a damage resistant coating, and a method for producing the damage resistant coating.

  In order to solve the above-described problems, the coating formed with the damage-resistant coating of the present invention includes a metal material, a plastics material, a ceramic material, and a damage-resistant coating containing vapor-grown carbon fibers in a synthetic resin matrix. It is formed on at least a part of the material surface of various composite materials.

  Specifically, the coating on which the damage resistant coating of the present invention is formed comprises a synthetic resin as a resin matrix, contains 3 to 40 parts by weight of vapor grown carbon fiber with respect to 100 parts by weight of the synthetic resin, The Knoop hardness of the damage coating is 40 Hk or more, and is characterized in that the damage coating is a coating formed on at least a part of the material surface.

  As a result, the coating on which the damage-resistant coating is formed has good mechanical properties such as long-term corrosion resistance, ductility, lubricity and impact resistance, and has damage resistance against sliding. The above objective is achieved. When the amount of vapor grown carbon fiber is less than 3 parts by weight with respect to 100 parts by weight of the synthetic resin, mechanical properties such as impact resistance are improved, but Knoop hardness is not so high. If the amount of the damage resistant coating is 3 parts by weight or more, the coating Knoop hardness is at least 40 Hk, and it has damage resistance against sliding. For example, the Knoop hardness of a coating formed of an inorganic paint of zinc powder is about 30 Hk, and the coating on which the damage resistant coating is formed can provide practically sufficient damage resistance. Moreover, when the amount exceeds 40 parts by weight, it becomes difficult to obtain a homogeneous thin film.

Vapor-grown carbon fiber refers to carbon fiber produced by thermal decomposition of hydrocarbons, and the carbon hexagonal network surface concentrically laminated around the fiber axis is well oriented in the fiber axis direction and is graphitizable. It's expensive. The true density is about 2.0 g / cm ³ , the fiber diameter is from several nm to several tens of μm, and the fiber length is generally around 150 μm.

  The Knoop hardness referred to here is a value obtained according to the “Knoop hardness test method” described in JIS standard Z2251.

  The coating on which the damage resistant coating of the present invention is formed comprises a synthetic resin as a resin matrix and contains 3 to 40 parts by weight of vapor-grown carbon fiber with respect to 100 parts by weight of the synthetic resin. A damage-resistant film having a torque coefficient value of 0.15 or less is a coating formed on at least a part of the material surface.

  As a result, the coating on which the damage-resistant coating is formed has good mechanical properties such as long-term corrosion resistance, ductility, lubricity and impact resistance, and has damage resistance against sliding. The above objective is achieved. As described above, when the amount of vapor grown carbon fiber is less than 3 parts by weight with respect to 100 parts by weight of the synthetic resin, mechanical properties such as impact resistance are improved, but Knoop hardness is not so high.

  The damage resistant coating can provide practically sufficient damage resistance when the torque coefficient value is 0.15 or less, and the coating on which the damage resistant coating is formed slides. Resistant to damage. That is, the torque coefficient value is an index indicating the physical property corresponding to the friction coefficient. When this value is 0.15 or less, the friction during sliding is reduced and damage caused by sliding can be sufficiently avoided. .

  Thus, the phenomenon in which damage to the damage resistant coating is avoided is considered as follows. First, in the damage-resistant coating, the presence of the vapor-grown carbon fibers uniformly dispersed in the synthetic resin increased the coating hardness as described above, making it difficult for deformation on the coating surface to occur. Can be mentioned. The other is that the toughness of the coating is enhanced by the presence of the vapor-grown carbon fibers, and the coating is not damaged by the shearing force generated at the sliding interface. That is, the vapor-grown carbon fiber is uniformly dispersed in the synthetic resin matrix, and the vapor-grown carbon fiber and the synthetic resin matrix are in a state in which the toughness of the film is exhibited (for example, the fiber is moderate due to stress load). It is considered that they are connected by expansion and contraction and pull-out. Furthermore, it is considered that vapor-grown carbon fiber has a good thermal conductivity and dissipates heat generated on the sliding surface, and exhibits an effect of reducing damage due to sliding (friction). Therefore, in the coating material having the above structure, the vapor-grown carbon fibers are suitably dispersed in the synthetic resin and are suitably bonded to the synthetic resin matrix. Moreover, the vapor growth carbon fiber has a structure or a structure in which damage resistance during sliding is exhibited.

  Further, the coating of the present invention has good mechanical properties such as long-term corrosion resistance, ductility, lubricity, impact resistance, etc. in addition to practically sufficient damage resistance against sliding. Moreover, when the amount exceeds 40 parts by weight, it becomes difficult to obtain a homogeneous thin film.

  The torque coefficient value referred to here is a value obtained according to the “set torque coefficient value” described in JIS standard B1186.

  Further, the coating on which the damage resistant coating of the present invention is formed, the damage resistant coating includes a synthetic resin as a resin matrix, and includes at least 9 parts by weight of vapor grown carbon fiber with respect to 100 parts by weight of the synthetic resin, The damage-resistant film having a Knoop hardness of 150 Hk or more is a coating formed on at least a part of the material surface.

  As a result, the film has a hardness equivalent to about 150 Hk, which is the Knoop hardness of galvanization, and further has damage resistance against high-addition sliding.

  In the covering having the above structure, the thickness of the coating can be set to 5 to 50 μm.

  Thus, by making a film into a thin film, the coating material which has the said film can make it easy to fit in a dimensional tolerance in the metal material used as a machine part.

  Further, in the covering having the above configuration, the synthetic resin is not particularly limited, and can be applied to any synthetic resin. For example, the synthetic resin can be selected according to the use. For example, use of a thermosetting resin is preferable because the hardness of the coating can be further increased.

  Moreover, in the coating of the said structure, it is preferable that it is either a phenol resin, a polyamideimide resin, an epoxy resin, a silicon resin, a water-system fluororesin, or a urethane resin.

  Moreover, in the coating material in which the damage-resistant film of this invention was formed, a pigment can be included.

  It is preferable to use a rust preventive pigment as the pigment. Long-term corrosion resistance is imparted by the addition of the rust preventive pigment.

  Moreover, in the coating material in which the damage-resistant film of this invention was formed, a lubricant can be included. By adding a lubricant, it is possible to control the coefficient of friction between the coating and the counterpart substance, and to further significantly reduce the wear caused by sliding.

  It is preferable that the lubricant contains at least one of fluororesin powder, molybdenum disulfide, or diamond nano powder.

  The damage-resistant coating material of the present invention is a damage-resistant coating material comprising a synthetic resin solution in which vapor-grown carbon fibers are dispersed, and is 3 to 40 weights with respect to 100 parts by weight of the solid component of the synthetic resin solution. Part of vapor-grown carbon fiber and 10 to 300 parts by weight of a polar solvent.

  As a result, it is possible to provide a film in which vapor-grown carbon fibers are suitably dispersed in a synthetic resin, and the coating on which this film is formed has good long-term corrosion resistance, ductility, lubricity, impact resistance, and the like. The above-mentioned object is achieved by having excellent mechanical characteristics and damage resistance against sliding. Further, it is possible to form a thin film. In addition, when the amount of vapor-grown carbon fiber is less than 3 parts by weight with respect to 100 parts by weight of the solid component of the synthetic resin solution, when it is less than 3 parts by weight, mechanical properties such as impact resistance are improved. Knoop hardness is not so high. Moreover, when it has a vapor growth carbon fiber exceeding 40 weight part, the viscosity of a damage-resistant coating material will become high, and will require time and effort to make it into a thin film form uniformly.

  In addition, it cannot be overemphasized that a synthetic resin solution may contain inorganic and / or organic solvents other than a polar solvent depending on the aspect of a synthetic resin. The solid component of the synthetic resin solution refers to a resin component that remains when the synthetic resin is cured to form a film.

  In the damage-resistant coating material having the above-described configuration, the polar solvent is pure water, alcohols, N-methyl-2-pyrrolidone, dimethylacetamide, methyl ethyl ketone, methyl isobutyl ketone, or a mixture of two or more of these. Preferably there is.

  In the damage-resistant coating material having the above-described configuration, the synthetic resin is not particularly limited, and any synthetic resin can be used. For example, the synthetic resin can be selected according to the application. The synthetic resin may be a liquid resin or a solid resin such as a powder. For example, use of a thermosetting resin is preferable because the hardness of the coating can be further increased.

  Moreover, in the damage-resistant coating material of the said structure, it is preferable that they are either a phenol resin, a polyamide-imide resin, an epoxy resin, a silicon resin, a water-system fluororesin, or a urethane resin.

  Moreover, it is preferable that the damage-resistant coating material of the said structure contains the pigment.

  Moreover, it is preferable that the damage-resistant coating material having the above-described configuration contains a lubricant.

  Furthermore, the lubricant preferably contains at least one of fluororesin powder, molybdenum disulfide, or diamond nano powder.

  The method for producing a damage resistant coating according to the present invention is a method for producing a damage resistant coating comprising a synthetic resin solution in which vapor-grown carbon fibers are dispersed, wherein 100 parts by weight of a solid component of the synthetic resin solution is added. The vapor grown carbon fiber was dispersed in the polar solvent using 3 to 40 parts by weight of the vapor grown carbon fiber and 10 to 300 parts by weight of the polar solvent. It includes a step of mixing a polar solvent and a synthetic resin.

  As a result, the vapor-grown carbon fibers can be uniformly dispersed in the synthetic resin solution. That is, in order to uniformly disperse the vapor-grown carbon fiber, it is necessary to surround the vapor-grown carbon fiber surface with a polar solvent in advance and then mix the polar solvent in which the vapor-grown carbon fiber is dispersed with the synthetic resin. It is effective for. Further, the amount of the polar solvent is preferably 10 to 300 parts by weight, and more preferably 30 to 150 parts by weight. However, depending on the method of forming the coating, the amount is not limited to this amount, and may be an amount that provides an appropriate viscosity of the damage resistant coating according to the method of forming the coating.

  The coating on which the damage-resistant coating film of the present invention is formed has good mechanical properties such as long-term corrosion resistance, ductility, lubricity and impact resistance, and has damage resistance against sliding. By adjusting the vapor growth carbon fiber in the damage resistant coating, a more excellent coating can be obtained. Moreover, the corrosion resistance according to a use or use environment can be provided by selecting the kind of synthetic resin. Addition of a pigment to the damage resistant coating can further improve the corrosion resistance. The addition of a lubricant to the damage resistant coating can further improve the sliding characteristics.

  The damage-resistant coating agent of the present invention can provide a thin damage-resistant coating film in which vapor-grown carbon fibers are uniformly dispersed. For this reason, a coating coated on a material used as a machine part can exhibit suitable characteristics and can easily be accommodated within dimensional tolerances.

  According to the method for producing a damage-resistant coating material of the present invention, a damage-resistant coating material suitable for dispersing a vapor-grown carbon fiber in a synthetic resin solution and providing a thin film with a damage-resistant coating material is provided. provide.

  Embodiments of the present invention will be described below.

  The coating formed with the damage resistant coating according to the present embodiment uses a synthetic resin as a resin matrix, and the synthetic resin matrix contains 3 to 40 parts by weight of vapor-grown carbon fibers with respect to 100 parts by weight of the synthetic resin. A damage resistant coating is formed on at least a portion of the surface of a material such as a metal material. When the Knoop hardness of the damage resistant coating is 40 Hk or more, practically sufficient damage resistance can be provided, and the coating on which the damage resistant coating is formed is a suitable machine part, It can be used as a fastening member. Furthermore, since the vapor grown carbon fiber contains at least 9 parts by weight with respect to 100 parts by weight of the synthetic resin and the Knoop hardness is 150 Hk or more, it can be applied to a higher load and has excellent damage resistance. Have.

  In addition, since the torque coefficient value of the damage resistant coating is 0.15 or less, the coating on which the damage resistant coating is formed in which friction during sliding is reduced and damage caused by sliding is sufficiently reduced. It becomes.

  As a method for obtaining a coating on which the damage resistant coating is formed, there is a method of applying a damage resistant coating made of a synthetic resin solution in which vapor-grown carbon fibers are dispersed to the material surface.

  In this embodiment, the damage-resistant coating agent has 3 to 40 parts by weight of vapor-grown carbon fiber dispersed in a synthetic resin solution containing a polar solvent with respect to 100 parts by weight of the solid component of the synthetic resin solution. Of course, depending on the mode of the synthetic resin, the synthetic resin solution may contain inorganic and / or organic solvents other than the polar solvent.

  The vapor grown carbon fiber is not particularly limited in shape such as fiber diameter and fiber length, but preferably has a fiber diameter of about 150 nm and an aspect ratio of about 500 or less. Further, the aspect ratio may be further reduced by cutting the vapor-grown carbon fiber by, for example, a method of cutting using ultrasonic waves or a method of treatment with an acid solution. The smaller the aspect ratio of the vapor grown carbon fiber, the easier the dispersibility of the vapor grown carbon fiber in the synthetic resin solution.

  The synthetic resin to be used is not particularly limited. For example, fluorine resin, polyamideimide resin, polyimide resin, phenol resin, epoxy resin, silicon resin, urethane resin, polyvinyl chloride resin, alkyd resin, acrylic resin, melamine resin, polystyrene resin , Vinyl ester resins, polyester resins, copolymers thereof, modified products, and mixtures of two or more thereof can be used. Preferably, it is at least one of a polyamide-imide resin, a phenol resin, an epoxy resin, a silicon resin, a water-based fluororesin, or a urethane resin. Further, a thermosetting resin is preferable because the hardness of the coating can be further increased.

  Examples of the polar solvent used include pure water, alcohols, N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc), methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK). The polar solvent is not limited to these, and may be determined in consideration of the vapor-grown carbon fiber to be used, the solubility with the synthetic resin to be used, the film formability, and the like.

  The amount of the polar solvent used is 10 to 300 parts by weight with respect to 100 parts by weight of the solid component of the synthetic resin solution. More preferably, it is 30 to 150 parts by weight.

  The manufacture of the damage-resistant coating material of this embodiment is performed according to the following procedure.

  First, a predetermined amount of polar solvent is put into a suitable container, and a predetermined amount of vapor-grown carbon fiber is put therein. The method for introducing the vapor-grown carbon fiber is not particularly limited, and it may be devised such that a large amount of vapor-grown carbon fiber is not charged at a time. At this time, the vapor-grown carbon fiber can be more reliably dispersed in the polar solvent by adding an appropriate amount of the dispersant to the polar solvent. As the dispersant, an anionic, cationic, nonionic or amphoteric surfactant can be used, and it may be selected according to the synthetic resin solution to be used. The amount of the dispersant added may be small, for example, about 1 to 2 w / v% with respect to the synthetic resin solution (1-2 g with respect to 100 ml of the synthetic resin solution).

  Next, the vapor growth carbon fiber is uniformly dispersed in a polar solvent. Examples of the dispersion method include a method of performing mechanical stirring and a method of using ultrasonic waves. As a mechanical dispersion method, for example, a commercially available homogenizer is used to rotate the solution by rotating a stirring blade or a stirring rod. The number of revolutions may be determined in consideration of the amount of vapor-grown carbon fiber introduced and the total amount of processing, but is generally 5000 to 15000 rpm. Moreover, it can disperse | distribute using a commercially available ultrasonic generator. These two methods may be used in combination.

  Next, the polar solvent in which the vapor grown carbon fiber is dispersed and the synthetic resin are mixed.

  Examples of the mixing at this time include a method of performing mechanical stirring and a method of using ultrasonic waves. As a mechanical dispersion method, for example, a commercially available homogenizer is used to rotate the solution by rotating a stirring blade or a stirring rod. The number of revolutions may be determined in consideration of the amount of vapor-grown carbon fibers added and the total amount of processing, but is generally 2000 to 5000 rpm. Moreover, it can disperse | distribute using a commercially available ultrasonic generator. These two methods may be used in combination. Moreover, you may add a pigment as needed. The pigment is a rust preventive pigment, and any of natural pigments, synthetic organic pigments, and synthetic inorganic pigments can be used, and examples thereof include metal complex oxides, chromium oxides, and organic pigments. The added amount of the pigment is preferably 1 to 30 parts by weight, and more preferably 5 to 20 parts by weight with respect to 100 parts by weight of the synthetic resin. The particle size of the pigment may be determined in consideration of the dispersibility and agglomeration property with respect to the synthetic resin solution, but is desirably as fine as possible. For example, those having an average particle size of 4 to 6 μm and a particle size mainly in the distribution range of 0.5 to 10 μm are preferable. Moreover, you may add a lubricant as needed.

  Examples of the lubricant include fluororesin powder, molybdenum disulfide, diamond nano powder, and the like. The addition amount of the lubricant may be about 0.5 to 10 parts by weight with respect to 100 parts by weight of the synthetic resin although it varies depending on the use environment of the coating. The maximum value of the average particle diameter of the lubricant is desirably 4 to 6 μm or less. The average particle size of the lubricant is preferably about 0.01 to 4 μm.

  Finally, when ultrasonic waves are applied to the synthetic resin in which the vapor-grown carbon fibers are dispersed using a commercially available ultrasonic generator, bubbles generated during the dispersion can be removed.

  Using this damage-resistant coating, metal materials such as carbon steel, stainless steel, aluminum, titanium, various alloys, ceramic materials such as alumina, zirconia, artificial graphite, glass, various plastics materials, various composite materials, etc. It is set as the coating by which a film is formed in at least one part of the material surface of this. The thickness of the coating can be a thin film of about 5 μm. By setting the thickness of the coating to 5 to 50 μm, for example, in the case of a metal material used as a machine part, it can be easily accommodated within a dimensional tolerance. Further, for example, a thick film of 1 mm or more may be used as necessary.

  In order to form a coating to form a coating, a method such as dipping, spraying or brushing can be applied. After coating, drying and heat treatment are performed to cure the resin, and a highly uniform coating is formed.

  Embodiments will be described below with reference to the tables and drawings.

  7 types of damage-resistant coating materials are prepared in which 2.4, 4.7 and 11 parts by weight of vapor-grown carbon fiber are dispersed with respect to 100 parts by weight of the solid component of a liquid resol type phenolic resin (synthetic resin). did.

  As the vapor grown carbon fiber, a commercially available product (manufactured by Showa Denko KK, VGCF®) was used. The vapor-grown carbon fiber has a typical fiber diameter of about 150 nm and a typical fiber length of 10 to 20 μm. The range of the aspect ratio is 10 to 500.

  To prepare the damage resistant coating, first, a predetermined amount of polar solvent (NMP) was put in a stainless steel container, and an anionic surfactant was added as a dispersant at a rate of 1 to 2 g per 100 ml of NMP. At this time, NMP used the same weight part as the amount of synthetic resin.

  A predetermined amount of vapor-grown carbon fiber was added little by little to this solution, and the mixture was stirred by hand with a stainless steel stirring rod for 2-3 minutes.

  Next, the polar solvent to which the vapor-grown carbon fiber was added was premixed by applying ultrasonic waves for about 30 minutes using a commercially available ultrasonic generator (frequency: 100 kHz) in a stainless steel container. At this time, it was confirmed that the closer to 100 kHz, the easier the dispersion.

  Next, using a commercially available homogenizer stirring device, the polar solvent with the vapor-grown carbon fibers added is rotated with four stainless steel stirring blades to uniformly disperse the vapor-grown carbon fibers in the polar solvent. I let you. The rotational speed of the stirring blade was between 5000 and 15000 rpm, and the rotational speed was increased as the amount of vapor-grown carbon fiber was increased. The stirring time at this time was about 15 minutes.

  Next, a predetermined amount of synthetic resin was added to the polar solvent in which the vapor grown carbon fiber was dispersed. The polar solvent and the synthetic resin in which the vapor-grown carbon fibers were dispersed were also premixed by applying ultrasonic waves having a frequency of up to 100 kHz using the above ultrasonic generator. In order to uniformly disperse the vapor-grown carbon fiber and the synthetic resin, the mixed solution containing the vapor-grown carbon fiber was stirred using the homogenizer stirring device and the stirring blade. When rotating in a synthetic resin containing a polar solvent, the number of rotations of the stirring blade was between 2000 and 5000 rpm, and the number of rotations was increased as the amount of vapor-grown carbon fiber increased. The stirring time was about 15 minutes.

  The mixed solution (damage-resistant coating material) obtained here was stirred again by applying ultrasonic waves having a frequency of up to 100 kHz using the above ultrasonic generator. By this stirring operation, the air bubbles present in the damage-resistant coating could be almost removed.

  The prepared damage resistant coating was transferred to a transparent glass bottle. The state of the damage resistant coating prepared by visual observation was observed, and it was confirmed that the vapor grown carbon fiber was uniformly dispersed in the resin solution.

  Next, SPCC cold-rolled steel sheet (length 150 mm, width 70 mm, thickness 0.8 mm) degreased using ethyl alcohol, a M20 bolt with a thread length of 100 mm, and a M20 hexagon with a height of 16 mm The entire surface of the nut was coated with a damage resistant coating by spray coating to form a coating. The coating was performed using a pressure-feed type air spray gun (WITER-61 type manufactured by Iwata: caliber 1.3 mm) under conditions of an air pressure of 0.29 to 0.34 MPa and a coating agent discharge rate of 95 to 200 ml / min. After the coating, it was dried in a drier and heat-treated at a temperature at which the resin was sufficiently cured (around 200 ° C.) to obtain a coating on which a film was formed.

  The thickness of the coating was adjusted to 40-50 μm. The thickness of the film was measured according to JIS standard K5600-1-7 using an electromagnetic film thickness meter (LZ-330 type, manufactured by Kett Science). Moreover, the cross section of the coating was observed with a scanning microscope, and it was confirmed that there were no significant voids or the like at the interface between the SPCC cold-rolled steel sheet and the coating film of the base material.

  The adhesion of the coating to the substrate (length 150 mm, width 70 mm, thickness 0.8 mm) was tested according to JIS standard K5600-5-6. As a result, it was confirmed that the coating adhered well to the substrate.

  The following film characteristic test was done about the 40-50 micrometers film formed in the surface of the SPCC cold-rolled steel plate which is a base material.

  The hardness of the film was evaluated by measuring pencil scratch hardness and Knoop hardness. The pencil scratch hardness was measured according to JIS standard K5600-5-4. The pencil scratch hardness was measured by the hardness (pencil hardness) at which no scar was formed on the film. The Knoop hardness was measured according to (JIS standard Z2251).

  The bendability was evaluated according to JIS standard K5600-5-4. At this time, it is judged by observing the film surface of the bent portion after being bent under a predetermined condition with a 40-fold microscope to confirm the presence or absence of cracking or peeling.

  About impact resistance, it measured according to the DuPont type of JIS specification K5600-5-3. A 1000 g weight having a different curvature radius at the tip is dropped onto the coating from a height of 50 cm, and then observed with a 40-fold microscope to confirm the presence or absence of cracking or peeling.

  For the fitting test using bolts and nuts, using a M20 bolt with a thread length of 100 mm and a M20 nut with a height of 16 mm, the torque coefficient value (friction resistance) of the screw part (bolt and nut set) And the destruction of the coating were evaluated. The bolt and nut were given an axial force of 20 tons. The torque coefficient value of the thread portion was obtained according to JIS standard B1186. Five test pieces were used each. The ratio of the portion where the bolt and nut coatings were damaged and lost was determined.

  Table 1 shows the property test results of the respective coatings made of each damage-resistant coating for Example 1, Example 2, and Comparative Examples 1 to 4.

FIG. 1 shows a graph in which the amount of vapor-grown carbon fibers with respect to 100 parts by weight of the synthetic resin of each coating is plotted on the horizontal axis and the Knoop hardness of each coating is plotted on the vertical axis for Example 1 and Example 2. Yes. Here, when the amount of vapor grown carbon fiber is zero, the Knoop hardness values of Comparative Example 3 are used for Example 1 and Comparative Example 4 for Example 2, respectively. Each data point was approximated by a quadratic polynomial curve, and the correlation coefficient (R ² ) was 0.988 (Example 1) and 0.972 (Example 2).

  In Table 1, about Example 1, the characteristic test result of each of the three types of coating films in which the amount of the vapor growth carbon fiber is 2.4, 4.7, and 11 parts by weight with respect to the phenol resin is shown.

  First, regarding the hardness, when the amount of the vapor-grown carbon fiber is 2.4 parts by weight with respect to the phenol resin, the Knoop hardness was 20 Hk, but the pencil scratch hardness was 7 H. The value was higher than the example value (6H). In the case of 2.4 parts by weight with the smallest amount of vapor-grown carbon fiber, it was 7H, and when the amount of vapor-grown carbon fiber was 4.7 parts by weight or more, the pencil hardness was 9H. The maximum hardness that can be measured is 9H. Of the hardnesses, the pencil scratch hardness indicates the hardness (pencil hardness) at which no scar was formed on the coating.

  And as for Knoop hardness, when the quantity of vapor growth carbon fiber is 11 weight part, Knoop hardness has shown 200Hk. Since the Knoop hardness of galvanization is about 150 Hk, it was shown that the coating film in which 11 parts by weight of vapor-grown carbon fiber is dispersed with respect to 100 parts by weight of phenol resin has a hardness higher than that of galvanization.

  According to FIG. 1, if the amount of vapor grown carbon fiber is at least 3 parts by weight with respect to the phenolic resin, it indicates at least 40 Hk, and if it is at least 9 parts by weight, it indicates 150 Hk.

  The bendability is obtained by bending a mandrel having a diameter shown in Table 1, and the smaller the mandrel diameter, the higher the ductility can be evaluated. The value of the diameter of the mandrel shows that when the amount of vapor-grown carbon fiber is 11 parts by weight, it becomes as small as 4 mm. Even if the amount of vapor-grown carbon fiber is increased, the ductility is not impaired, but rather the ductility is increased. ing.

  As for the impact resistance, the radius of curvature of the weight was 3 mm even in the case of 2.4 parts by weight with the smallest amount of vapor-grown carbon fiber. By adding the vapor growth carbon fiber, the impact resistance is remarkably improved, and a film which is difficult to peel off is formed.

  The bolt / nut fitting test shows that the smaller the torque coefficient value, the smaller the friction coefficient, the better the lubricity, and the higher the ductility. The film breaking state is an index corresponding to the mechanical strength of the film. When the vapor-grown carbon fiber was added, the torque coefficient value was lowered, and when the vapor-grown carbon fiber was 4.7 parts by weight, the coating was not broken. Even when the amount of vapor-grown carbon fiber is 2.4 parts by weight, the torque coefficient value is sufficiently small, and the destruction of the coating is as small as about 5% or less.

  As a synthetic resin, 2.3, 4.6, and 11 parts by weight of vapor grown carbon fiber were dispersed with respect to the solid component of the polyamideimide resin in the same manner as in Example 1 except that the polyamideimide resin was used. Three types of damage resistant coatings were prepared. Moreover, the coating material in which the film was formed on the base material similar to Example 1 like Example 1 was produced.

  Also in Example 2, the thickness of the coating was adjusted to 40 to 50 μm. The thickness of the coating was also measured in the same manner as in Example 1. Also in Example 2, the cross section of the coating was observed with a scanning microscope, and it was confirmed that there were no significant voids or the like at the interface between the SPCC cold-rolled steel sheet and the coating.

  Further, the adhesion of the coating to the substrate (length 150 mm, width 70 mm, thickness 0.8 mm) was also tested in the same manner as in Example 1. As a result, also in Example 2, it was confirmed that the coating adhered well to the substrate.

  In the same manner as in Example 1, the same coating property test was performed on the 40-50 μm coating formed on the surface of the SPCC cold rolled steel sheet as the substrate.

  In the characteristic test of each coating film of Example 2 shown in Table 1, the following results were shown.

  The pencil scratch hardness indicates the hardness (pencil hardness) at which no scar was formed on the coating. In the case of 2.3 parts by weight with the smallest amount of vapor-grown carbon fiber, it is 7H. When the amount of vapor-grown carbon fiber is increased, the pencil hardness is increased and the hardness of the film is increased. Yes.

  And, Knoop hardness showed Knoop hardness of 180 Hk when the amount of vapor-grown carbon fiber was 11 parts by weight with respect to the polyamide-imide resin, indicating that it had a hardness equal to or higher than galvanization.

  According to FIG. 1, as in Example 1, when the amount of vapor grown carbon fiber is 3 parts by weight with respect to the polyamide-imide resin, at least 40 Hk is indicated, and when it is 9 parts by weight, 150 Hk is indicated. It will be.

  The bendability is obtained by bending a mandrel having a diameter shown in Table 1, and the smaller the mandrel diameter, the higher the ductility can be evaluated. The value of the diameter of the mandrel is as small as 6 mm when the amount of the vapor-grown carbon fiber is 11 parts by weight, indicating that the ductility is increased by increasing the amount of the vapor-grown carbon fiber.

  As for the impact resistance, the radius of curvature of the weight was 6 mm in the case of 2.3 parts by weight with the smallest amount of vapor-grown carbon fiber, and 3 mm in the other cases.

The bolt / nut fitting test shows that the smaller the torque coefficient value, the smaller the friction coefficient, the better the lubricity, and the higher the ductility. The film breaking state is an index corresponding to the mechanical strength of the film. When the amount of vapor-grown carbon fiber increased, the torque coefficient value rather decreased, and the coating was not broken. Even when the amount of vapor-grown carbon fiber is 2.3 parts by weight, the torque coefficient value is sufficiently small, and the destruction of the coating is as small as about 5% or less.
(Comparative Example 1)
2.4, 4.7, and 11 parts by weight of Example 1 were used except that carbon black (manufactured by Ketjen Black EC, particle size 0.04 μm) was used instead of vapor grown carbon fiber. Three types of damage-resistant coating materials in which carbon black was dispersed were prepared, and coatings were respectively prepared.

  Also in Comparative Example 1, the thickness of the coating was adjusted to 40 to 50 μm. The thickness of the coating was also measured in the same manner as in Example 1. Also in Comparative Example 1, the cross section of the coating was observed with a scanning microscope, and it was confirmed that there were no significant voids or the like at the interface between the SPCC cold-rolled steel sheet and the coating.

  Further, the adhesion of the coating to the substrate (length 150 mm, width 70 mm, thickness 0.8 mm) was also tested in the same manner as in Example 1. As a result, also in Comparative Example 1, it was confirmed that the coating adhered well to the substrate.

  In the same manner as in Example 1, the same coating property test was performed on the 40-50 μm coating formed on the surface of the SPCC cold rolled steel sheet as the substrate.

  Table 1 shows the characteristic test results of the coating films of Comparative Example 1, in which the amount of carbon black is 2.4, 4.7, and 11 parts by weight with respect to 100 parts by weight of the phenol resin.

In Table 1, even when the amount of carbon black was increased, the values of hardness, bendability and impact resistance showed little change, and no improvement in these characteristics was observed. In the fitting test using bolts and nuts, about 2.4% by weight of carbon black was observed even when the torque coefficient was as small as 0.15 in the case of 2.4 parts by weight. When the amount of black was increased, the torque coefficient tended to decrease slightly, but no film breakage was observed.
(Comparative Example 2)
Three types of resistance in which 2.3, 4.6 and 11 parts by weight of carbon black were dispersed in the same manner as in Example 2 except that the carbon black used in Comparative Example 1 was used instead of the vapor grown carbon fiber. A damaging coating was prepared and each coating was prepared.

  Also in Comparative Example 2, the thickness of the coating was adjusted to 40 to 50 μm. The thickness of the coating was also measured in the same manner as in Example 1. Also in Comparative Example 2, the cross section of the coating was observed with a scanning microscope, and it was confirmed that there were no significant voids or the like at the interface between the SPCC cold-rolled steel sheet and the coating.

  Further, the adhesion of the coating to the substrate (length 150 mm, width 70 mm, thickness 0.8 mm) was also tested in the same manner as in Example 1. As a result, in Comparative Example 2, it was confirmed that the coating was in good contact with the substrate.

  In the same manner as in Example 1, the same coating property test was performed on the 40-50 μm coating formed on the surface of the SPCC cold rolled steel sheet as the substrate.

  Table 1 shows the characteristic test results of the coating films of Comparative Example 2 in which the amount of carbon black is 2.3, 4.6, and 11 parts by weight with respect to 100 parts by weight of the polyamideimide resin.

In Table 1, even when the amount of carbon black was increased, the values of hardness, bendability and impact resistance did not change much, and no improvement in these characteristics was observed. In the fitting test using bolts and nuts, about 2.3% of the coating film was broken even if the torque coefficient was as small as 0.15 in the case of 2.3 parts by weight of carbon black. When the amount of black was further increased, the torque coefficient tended to decrease slightly, but no film breakage was observed.
(Comparative Example 3)
A damage-resistant coating consisting essentially of the phenolic resin and polar solvent (NMP) used in Example 1 was prepared without using any vapor-grown carbon fibers. The same weight of phenolic resin and polar solvent was placed in a stainless steel container and stirred until a uniform coating was made until the mixture was uniformly mixed. Using this coating agent, a coating was prepared according to the method shown in Example 1.

  Also in Comparative Example 3, the thickness of the coating was adjusted to 40 to 50 μm. The thickness of the coating was also measured in the same manner as in Example 1. Also in Comparative Example 3, the cross section of the coating was observed with a scanning microscope, and it was confirmed that there were no significant voids or the like at the interface between the SPCC cold-rolled steel sheet and the coating.

  Further, the adhesion of the coating to the substrate (length 150 mm, width 70 mm, thickness 0.8 mm) was also tested in the same manner as in Example 1. As a result, also in Comparative Example 3, it was confirmed that the coating adhered well to the substrate.

  In the same manner as in Example 1, the same coating property test was performed on the 40-50 μm coating formed on the surface of the SPCC cold rolled steel sheet as the base material.

  Table 1 shows the characteristic test results of the respective films made of the damage-resistant coating material in Comparative Example 3.

As shown in Comparative Example 3 of Table 1, in the case of a film made only of a phenol resin, the pencil scratch hardness is 6H, the Knoop hardness is 18Hk, the diameter of the mandrel showing bendability is 6 mm, and the curvature of the weight showing impact resistance. The radius was 9 mm, the torque coefficient in the fitting test using bolts and nuts was 0.18, and about 10% of the coating was destroyed.
(Comparative Example 4)
A vapor-resistant carbon fiber was not used at all, and a damage-resistant coating consisting essentially of the polyamideimide resin and polar solvent (NMP) used in Example 2 was prepared in the same procedure as in Comparative Example 3, A coating was made.

  Also in Comparative Example 4, the thickness of the coating was adjusted to 40 to 50 μm. The thickness of the coating was also measured in the same manner as in Example 1. Also in Comparative Example 4, the cross section of the coating was observed with a scanning microscope, and it was confirmed that there were no significant voids or the like at the interface between the SPCC cold-rolled steel sheet and the coating.

  Further, the adhesion of the coating to the substrate (length 150 mm, width 70 mm, thickness 0.8 mm) was also tested in the same manner as in Example 1. As a result, also in Comparative Example 4, it was confirmed that the coating adhered well to the substrate.

  In the same manner as in Example 1, the same coating property test was performed on the 40-50 μm coating formed on the surface of the SPCC cold rolled steel sheet as the base material.

  Table 1 shows the characteristic test results of the film made of the damage-resistant coating material in Comparative Example 4.

  As shown in Comparative Example 4 in Table 1, in the case of a film made only of polyamide-imide resin, the pencil scratch hardness is 6H, the Knoop hardness is 15Hk, the diameter of the mandrel showing bendability is 6mm, and the weight showing impact resistance The radius of curvature was 9 mm, the torque coefficient in the fitting test using bolts and nuts was 0.17, and about 15% of the coating was destroyed.

  The damage-resistant coating of the present invention, the damage-resistant coating, and the manufacturing method of the damage-resistant coating are made of various fastening parts such as bolts and nuts, bearings, various seals, fastening flanges, washers, brakes. Used for mechanical parts such as shoes, jack parts, and sliding parts of semiconductor manufacturing equipment. It can also be used for various environmental barrier lining coatings.

It is a figure which shows the relationship between the quantity of the vapor growth carbon fiber with respect to 100 weight part of synthetic resins of a film | membrane, and the Knoop hardness of each film | membrane about the damage resistant film of the coating which concerns on Example 1 and Example 2. FIG.

Claims (10)

A damage-resistant coating material for bolt / nut surface coating, comprising a synthetic resin matrix, vapor-grown carbon fiber, and a polar solvent. The damage resistant coating for bolt / nut surface coating according to claim 1, comprising 3 to 40 parts by weight of the vapor-grown carbon fiber with respect to 100 parts by weight of a solid component of the synthetic resin matrix. The bolt / nut surface according to claim 1 or 2, wherein the synthetic resin is at least one selected from the group consisting of a phenol resin, an epoxy resin, a polyurethane resin, a silicon resin, a polyamideimide resin, and a water-based fluororesin. Damage resistant coating for coatings. The damage resistant coating for bolt / nut surface coating according to claim 1 or 2, wherein the synthetic resin is a thermosetting resin. The damage resistant coating for bolt / nut surface coating according to any one of claims 1 to 4, further comprising a pigment and / or a lubricant. 6. The polar solvent according to claim 1, wherein the polar solvent is at least one selected from the group consisting of pure water, alcohols, N-methyl-2-pyrrolidone, dimethylacetamide, methyl ethyl ketone, and methyl isobutyl ketone. Damage resistant coating for bolt and nut surface coatings. A coating comprising a bolt / nut surface coated with the damage resistant coating for a bolt / nut surface coating according to any one of claims 1 to 6 on at least a part of the bolt / nut surface.   The coating according to claim 7, wherein the Knoop hardness of the coating is 40 Hk or more.   The coating according to claim 7 or 8, wherein the torque coefficient of the coating is 0.15 or less. The coating according to any one of claims 7 to 9, wherein the thickness of the coating is 5 to 50 µm.