JP2007054749A - Coating layer and its forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating layer which is capable of assuring a sufficient non-adhesiveness to a self-adhesive material without using silicone oil and to provide a forming method thereof. <P>SOLUTION: The coating layer for covering a substrate 1 is provided with a surface layer 5 formed from a fluorine resin layer containing 10 wt.%-50 wt.% of a crosslinking fluorine resin and the arithmetic average height Ra of the surface profile curve of the surface layer is 1.5 μm-25 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a coating layer and a method for forming the same, and in particular, a non-adhesive coating suitable for facilities and apparatuses that handle adhesive materials, for example, facilities for manufacturing adhesive tapes, facilities using adhesive tapes, and molds for molding rubber. The present invention relates to a layer and a method for forming the layer.

  In facilities handling adhesives such as adhesive tape, how to prevent adhesion of adhesives is an important issue. For example, in the case of an adhesive tape roll, the adhesive tape adheres to the roll surface, and tape meandering, entanglement, tape breakage, etc. occur frequently, resulting in a decrease in productivity and quality.

  As countermeasures for this, conventional methods such as applying silicone oil to the surface of a substrate such as a roll or coating a silicone resin or fluororesin, a method of treating the surface of a substrate such as a roll by spraying or blasting, or these The non-adhesive coating method which combined these has been performed (for example, refer patent documents 1-2).

On the other hand, for the purpose of improving the abrasion resistance of fluororesin and reducing the surface roughness, a method is proposed in which a cross-linked fluororesin obtained by subjecting the fluororesin to a cross-linking reaction treatment is coated on a printer roller and polished. (For example, refer to Patent Document 3).
JP-A-5-228423 JP-A-5-68935 JP 2003-268296 A

  However, in the method of applying silicone oil, there is a problem that the silicone oil is transferred to a sticky product, and there are cases in which the stickiness of a product that should have stickiness is lowered and a defect occurs. Furthermore, even with a method of coating a silicone resin, durability such as hardness was not sufficient.

  In addition, in the method using a cross-linked fluororesin, for example, the release property and abrasion resistance of a roller with respect to toner-printed printing paper can be improved to some extent, but the degree is not sufficient, and further improvement is desired. It was. Moreover, it was unclear what effect it had on adhesives such as adhesive tapes.

  In general, as for adhesives such as adhesive tapes, there are many cases where non-adhesiveness cannot be ensured except for the silicone oil having the above problems. Especially for adhesive tapes, there is currently no effective maintenance-free countermeasure, and it is left unattended.

  The present invention has been made to solve the above-mentioned problems, and its object is to provide a coating layer capable of ensuring sufficient non-adhesiveness to an adhesive without using silicone oil or the like, and a method for forming the same Is to provide.

  The coating layer of this invention is a coating layer which coat | covers a base material, Comprising: The surface layer formed from the fluororesin layer which contains 10 to 50 weight% of crosslinked fluororesins is provided. And the arithmetic mean height Ra of the contour curve of a surface layer is 1.5 micrometers-25 micrometers.

  The above-mentioned cross-linked fluororesin means “cross-linked polymer (Chemical Dictionary: Tokyo Chemical Doujin (1989) p. 1774”) in which the fluororesin is cross-linked (see Patent Document 3). Since it has a typical network structure and does not flow even at high temperatures, the cross-linked fluororesin in the fluororesin that forms the surface layer does not completely melt into the normal fluororesin, In this case, the present inventors use a fluororesin layer containing a cross-linked fluororesin as a non-adhesive coating layer. The area of the dispersed cross-linked fluororesin is more stable and harder than the surroundings, resulting in a substantial reduction in adhesion (reduction due to chemical and mechanical interactions) upon contact with the adhesive tape. This At this idea stage, it is thought that the surface of the fluororesin layer containing the crosslinkable fluororesin actually forms geometrically large unevenness (forms a rough surface state). There wasn't.

  However, when the inventors conducted an experiment for confirming the above idea, by including 10% by weight or more of the crosslinkable fluororesin, if the film thickness is equal to or less than a predetermined thickness, the fluororesin layer is formed on the surface. It has been found that the arithmetic average height Ra of the contour curve is 1.5 or more. That is, it was confirmed that a roughened surface effective for non-adhesiveness can be obtained without particularly roughening the base. For this reason, in addition to the chemical and mechanical interactions described above, the geometric shape effect (the effect of reducing the pure contact area) was also added, and it was confirmed that the non-adhesive action on the adhesive tape was improved. . Moreover, as will be described later, in addition to the roughening specific to the fluororesin containing the cross-linked fluororesin, the fluororesin containing the crosslinkable fluororesin is improved by roughening the base and increasing the level of surface roughening. It was confirmed that the non-adhesive action of the layer (surface layer) could be further improved.

  The reason why the lower limit of the arithmetic average height Ra of the contour curve of the surface layer is 1.5 is that if Ra is less than 1.5, non-adhesive improvement due to roughening cannot be expected, and the cross-linked fluororesin is changed to a fluororesin. This is because the meaning of mixing and use is diminished. Further, when the Ra exceeds 25 μm, the large unevenness may damage an adhesive such as an adhesive tape. The arithmetic average height Ra of the contour curve is in accordance with JISB0601: 2001.

  Moreover, the reason why the lower limit of the ratio of the cross-linked fluororesin in the fluororesin forming the surface layer is 10% by weight is that when the content is less than 10% by weight, almost no improvement in non-adhesiveness in the surface layer is observed. In addition, when the ratio of the cross-linked fluororesin in the surface fluororesin becomes 10% by weight or more, the surface layer naturally becomes roughened, but it should be noted that the tendency becomes stronger as the surface layer is thinner. It is. That is, the higher the ratio of the cross-linked fluororesin in the fluororesin of the surface layer and the thinner the thickness of the surface layer, the greater the arithmetic average height Ra of the contour curve of the surface layer, and the non-adhesiveness is improved. On the other hand, the upper limit of 50% by weight of the above ratio is because if it exceeds 50% by weight, it is difficult to form a film, it becomes mechanically brittle, and defects are likely to occur.

  A more desirable range of the ratio of the cross-linked fluororesin in the fluororesin forming the surface layer is 15% by weight to 45% by weight. In addition, since there is currently no method for accurately analyzing the ratio of the cross-linked fluororesin in the fluororesin forming the surface layer (method for measuring the weight% of the cross-linked fluororesin in the coating layer state), the above ratio forms the surface layer. The ratio of the weight ratio in the coating material is small, but the fluctuation range of the weight ratio when changing from the coating material to the surface layer is small. For example, the above-mentioned fluctuation range is, if any, crosslinked fluororesin is more unstable than normal fluororesin with respect to heating, but does not significantly decrease by controlling the baking temperature.

  The thickness of the surface layer is preferably in the range of 5 μm to 300 μm. When the surface layer is roughened, due to the rough surface (irregularity) of the surface, the thickness of the surface layer becomes extremely thin in the shadow of the surface unevenness depending on the method of forming the surface layer. The thickness tends to increase and vary greatly. When the surface layer is roughened, the surface layer needs to be formed in a concavo-convex shape so as to follow the concavo-convex shape of the arithmetic average height of the contour curve in the base layer, and thus the thickness cannot be increased excessively. Further, when the content of the cross-linked fluororesin in the surface layer is small, when the surface layer thickness is increased, the arithmetic average height Ra of the contour curve of the surface layer is likely to decrease, and a desired rough surface level cannot be obtained. If the surface layer has a thickness of less than 5 μm, the non-adhesive performance (due to chemical interaction) of the surface layer containing the cross-linked fluororesin cannot be obtained at that location. Further, if there is a portion where the thickness of the surface layer exceeds 300 μm, both the rough surface level resulting from the inclusion of the cross-linked fluororesin and the rough surface level reflecting the rough surface state of the base are lowered, and the surface layer As a result, the level of the rough surface decreases, and the non-adhesive performance decreases. In addition, when forming a surface layer on a foundation | substrate, you may give the primer for fluororesins to the foundation | substrate surface.

  You may form said surface layer on a base material. Thereby, a non-adhesive coating layer can be formed at low cost. In this case, the surface roughness of the surface layer can be increased by increasing the proportion of the cross-linked fluororesin in the surface layer without subjecting the substrate to surface roughening (blasting, etc.) and making the surface layer thickness a predetermined value (for example, 40 μm) or less. The surface level reflecting the rough surface state of the base may be formed by subjecting the base material to a roughening treatment such as a blast treatment.

  When roughening the substrate, the arithmetic average height Ra of the contour curve of the substrate surface is preferably 25 μm or less. When the surface of the base material is roughened such as blasting, the surface level of the surface layer can be improved at a low cost, and a surface layer reflecting the surface level can be formed. The lower limit of the substrate surface is desirably 2 μm. When the Ra on the substrate surface is less than 2 μm, it is difficult to make the surface rough surface level 1.5 μm or more when the cross-linked fluororesin content is low or the surface layer thickness is a predetermined value or more. When the Ra of the contour curve of the base material (base) subjected to the chemical treatment exceeds 25 μm, the unevenness (rough surface) of the surface layer formed thereon becomes too large, and the large unevenness causes the adhesive such as an adhesive tape to be removed. It may be damaged.

Moreover, the inorganic material layer which is located between a base material and a surface layer and whose arithmetic mean height Ra of the contour curve of the surface of the surface layer side is 25 micrometers or less can be further provided. Thereby, by selecting an inorganic material of the inorganic material layer, Ra of the contour curve can be easily increased in a range of 25 μm or less. Moreover, in the case of a metal that is frequently used as a base material, it is possible to firmly fix the base material using a metal (inorganic material) of the same quality. Furthermore, the coating layer of the present invention can be hardened by ensuring the hardness. The above-mentioned inorganic material layer is made up of Rockwell hardness HRC (JIS
Z 2245) can be formed of 30 or more inorganic materials.

  Here, “the surface layer inheriting or reflecting the rough surface of the roughened base (base material or inorganic material layer)” means that the surface layer is formed along the rough surface of the base surface, and as a result, the surface layer This means that the formation of a rough surface (unevenness) is promoted, and there may be inconsistencies. For example, when the inorganic material layer is porous, a recess may be formed in the surface layer corresponding to the porous hole, and when the diameter of the porous hole is small on the surface, the recess may not be formed. is there. It is desirable that the surface layer is formed with a thin thickness so as to reflect the unevenness without burying the unevenness of the base.

  The layer thickness of the inorganic material layer can be 10 μm to 300 μm. When the layer thickness of the inorganic material layer is less than 10 μm, it is difficult to form a uniform layer, and when it exceeds 300 μm, the inorganic material layer is peeled off from the substrate due to the residual internal stress of the formed inorganic material layer.

  Moreover, the inorganic material which comprises an inorganic material layer can be used as a self-fluxing alloy. Thus, by spraying a self-fluxing alloy, Ra of the contour curve of the base surface can be easily increased as a dense base without fusing. Depending on the type of inorganic material and the remelting temperature, when fusing, it becomes difficult to ensure the contour curve Ra without surface irregularities. When a self-fluxing alloy is used for the inorganic material layer, for example, a dense layer can be obtained without remelting after spraying, and thus Ra can be easily secured.

  Ceramic particles having a particle size of 50 μm or less can be included in the inorganic material layer. Thereby, it becomes easier to secure the Ra of the contour curve of the inorganic material layer.

  The surface layer may further have an intermediate fluororesin layer at the bottom. Thereby, the thickness of a coating layer can be made more than predetermined value. Since the cross-linked fluororesin is more expensive than a normal fluororesin, it is more advantageous to use a normal fluororesin to ensure the thickness. However, the intermediate fluororesin layer may be formed of a cross-linked fluororesin.

  The method for forming a coating layer of the present invention is a method for forming a coating layer that covers a substrate. In this forming method, a surface layer having an arithmetic average height Ra of a contour curve of 1.5 μm to 25 μm is formed of a fluororesin containing 10% by weight to 50% by weight of a crosslinked fluororesin. According to this forming method, (1) the film thickness is adjusted according to the weight% of the cross-linked fluororesin in the fluororesin, and the rough surface level of the surface layer is 1.5 μm to 25 μm, or (2) When the rough surface level of the surface layer is further improved, in addition to the above (1), the rough surface level of the base (base material or inorganic material layer) can be increased.

  According to the coating layer and the method of forming the same of the present invention, non-adhesiveness to an adhesive such as an adhesive tape is remarkably superior to a roughened ordinary fluororesin coating layer. Can provide a non-adhesive coating layer that can cope with an adhesive that has been considered to have no effective countermeasure.

Next, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)

  FIG. 1 is a cross-sectional view showing a coating layer in Embodiment 1 of the present invention. In FIG. 1, a fluororesin primer treatment is performed on the surface of a substrate 1 to form a fluororesin primer layer 3. The fluororesin primer 3 means a surface that has been subjected to a fluororesin primer treatment, and it is not necessary to have a fluororesin primer layer that is identified as a continuous layer on the surface. Good. The surface layer 5 is formed of a fluororesin layer containing 10% by weight or more of a crosslinked fluororesin. The method for forming the surface layer 5 can be performed by the method described in the third embodiment.

The point in the present embodiment is that even if the surface (base material) on which the surface layer is formed is not subjected to the surface roughening treatment, if the ratio of the cross-linked fluororesin in the surface layer 5 is 10% by weight or more, When the film thickness is a predetermined value or less, for example, 50 μm or less, the surface layer is naturally roughened, and the arithmetic average height Ra of the contour curve is increased. That is, the surface layer 5 is roughened even if the surface of the substrate 1 is not roughened. Satisfactory non-adhesive performance can be obtained by the rough surface state of the surface layer and the crosslinked fluororesin. For example, even if it is a flat base, when the ratio of the cross-linked fluororesin in the surface fluororesin layer is 17% by weight and the surface layer thickness is 40 μm, the arithmetic average height Ra 2.5 μm of the surface layer contour curve is obtained. be able to. In addition, when the ratio of the cross-linked fluororesin in the surface fluororesin layer is 31% by weight and the surface layer thickness is 20 μm to 90 μm, the arithmetic average height Ra 4.9 μm of the contour curve of the surface layer can be obtained.
(Embodiment 2)

  FIG. 2 is a diagram showing a coating layer in the second embodiment of the present invention. The present embodiment is characterized in that the underlying rough surface layer 1a is formed on the surface of the substrate 1 without using an inorganic material layer. The arithmetic average height Ra of the contour curve of the rough surface layer 1a of the base material 1 can be easily adjusted by adjusting the type of blasting material for the base material, the particle size, the impact speed to the base material, the impact angle, etc. Can be adjusted within a range of 2 to 25 μm. In this embodiment, since the inorganic material layer is not used, the process of forming the coating layer is simplified, and savings can be made in terms of necessary materials.

The base material 1 is subjected to blasting to roughen the surface, and the arithmetic average height Ra of the contour curve of the rough surface layer 1a is set to a range of 2 to 25 μm. A baking process is performed. Thereafter, the surface layer 5 is formed of a fluororesin containing 10 wt% to 50 wt% of the crosslinked fluororesin. The method for forming the surface layer 5 can be performed by the method described in the third embodiment.
(Embodiment 3)

  FIG. 3 is a cross-sectional view showing a coating layer according to Embodiment 3 of the present invention. In the coating layer in the present embodiment, the inorganic material layer 2 constituting the base is formed on the substrate 1, and the fluororesin film 5 is formed on the inorganic material layer 2 with the fluororesin primer 3 interposed therebetween. ing. The fluororesin primer 3 means a surface that has been subjected to a fluororesin primer treatment, and it is not necessary to have a fluororesin primer layer that is identified as a continuous layer on the surface. Good. The surface layer 5 is formed of a fluororesin containing 10 to 50% by weight of a cross-linked fluororesin. An intermediate fluororesin layer may be inserted between the fluororesin primer 3 and the surface layer 5.

  The inorganic material layer 2 that is the base of the surface layer is roughened, and the arithmetic average height Ra of the contour curve is in a range of 25 μm or less. The rough surface state of the inorganic material layer 2 is reflected on the surface layer 5 containing the crosslinked fluororesin, and a rough surface is formed on the surface layer 5.

  The inorganic material constituting the inorganic material layer 2 is, for example, (M1) iron-based metals such as soft iron and steel, (M2) stainless steel-based metals such as SUS304 and SUS316, (M3) nickel-based, cobalt-based, and molybdenum-based simple substances. Or at least 1 sort (s), such as an alloy and (M4) Ni-Cr light alloy, are used. These metals may be mixed with ceramics such as tungsten carbide, chromium oxide, alumina, titanium oxide, zirconia, and yttria. In the present invention, the inorganic material layer is preferably porous from the viewpoint of maintaining the fluororesin film for a long period of time. In the case of a porous material, the fluororesin on the surface layer is impregnated in the porous material, and the bond is strengthened by the anchor effect.

  When the inorganic material layer 2 is formed by a thermal spraying method, the inorganic material is preferably sprayed with a powder having a particle diameter of 5 μm to 120 μm. When the particle size is smaller than 5 μm, the arithmetic average height Ra of the contour curve of the inorganic material layer to be molded becomes smaller than 2 μm, and the meaning of forming the inorganic material layer is diminished, and when it is larger than 120 μm, the inorganic material layer This is not preferable because the arithmetic average height Ra of the contour curve exceeds 25 μm. When ceramic particles are mixed and used, the particle size is preferably 50 μm or less because the ceramic particles are not melted by thermal spraying. Particles exceeding 50 μm are not preferable because the arithmetic average height Ra of the contour curve is rougher than 25 μm. In the thermal spraying method, a Ni—Cr self-fluxing alloy is particularly preferable because the particles are hard and excellent in wear resistance. A Ni—Cr self-fluxing alloy containing 5 to 50% by weight of ceramic powder such as tungsten carbide can also be preferably used.

  The fluororesin that forms the fluororesin film (surface layer) 5 needs to contain a cross-linked fluororesin. In addition to the crosslinked fluororesin, one or more of hexafluoropropylene-tetrafluoroethylene copolymer (FEP), tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), and polytetrafluoroethylene (PTFE) Can be used. In addition, when arrange | positioning layers other than the surface layer which affects non-adhesiveness, for example, an intermediate | middle fluororesin layer, a bridge | crosslinking fluororesin is not necessarily required for an intermediate | middle fluororesin layer.

  The cross-linked fluororesin refers to a cross-linked polymer in which the fluororesin is cross-linked. The cross-linked polymer has a three-dimensional network structure and does not flow even at high temperatures. For this reason, the cross-linked fluororesin in the fluororesin forming the surface layer is dispersed in the normal fluororesin in units of regions of the cross-linked fluororesin without completely melting in the normal fluororesin. The disperse hard and cross-linked fluororesin region which is different from the surroundings further enhances the effect of the rough surface state (irregular shape).

  One important point is that the arithmetic mean Ra of the contour curve of the fluororesin surface layer naturally increases as the proportion of the cross-linked fluororesin in the fluororesin increases. As a result, even with a flat substrate, the reduction of the geometric contact area is added to the chemical and mechanical interaction, and the non-adhesiveness is improved.

  Another important point is that the non-tackiness is further improved when the base is roughened. That is, the fluororesin including the cross-linked fluororesin, in which the rough surface level is greatly emphasized by the ground, exhibits the following state. : A layer in which hard cross-linked fluororesin (with non-adhesiveness) dissimilar to the surroundings is placed on the surface layer in a normal non-adhesive fluororesin so that the surface layer follows the rough surface (unevenness) of the base To have a rough surface. This brings about an effect different from the effect of simply dispersing ceramics. For this reason, the reduction effect of the contact area by unevenness | corrugation can be strengthened by the effect | action different from ceramics. The heterogeneous hard cross-linked fluororesin region mainly located in the convex part can emphasize the shape effect of the unevenness even if the degree of unevenness of the base is small, and therefore the degree of unevenness of the surface layer is small, The non-adhesiveness with respect to an adhesive thing can be improved greatly. As a result, for example, in the case of a member in which a large load is applied to the surface layer, it is possible to suppress a side effect that causes stress concentration in the concave and convex portions and causes cracks. In addition, there is a possibility that damage to the type of adhesive tape that requires attention to handling that may be damaged due to unevenness of the surface layer can be prevented.

  The crosslinked fluororesin in the fluororesin film (surface layer) 5 is preferably 10% by weight to 50% by weight, and more preferably 15% by weight to 40% by weight. If it is less than 10% by weight, almost no improvement in non-adhesiveness due to the mixing of the cross-linked fluororesin is observed, and if it exceeds 50% by weight, it is difficult to form a film and it becomes mechanically brittle, and defects tend to occur.

  When forming the surface layer 5 or the intermediate | middle fluororesin layer on the inorganic material layer 2, a commercially available primer for fluororesins can be used as needed.

  <Method for Forming Coating Layer>: Next, a method for forming the non-adhesive coating layer shown in FIG. 3 will be described.

  First, the aforementioned inorganic material layer 2 is formed on the surface of the substrate 1. The substrate 1 is a part or member of equipment that handles adhesives such as rolls, slit blades, floating nozzles, molds, troughs, hoppers, and storage tanks. Usually, metals such as iron such as soft iron and cast iron, stainless steel such as SUS304 and SUS316, and aluminum such as A5052 are used. However, the material of the substrate 1 is not particularly limited as long as it does not melt or deteriorate at the heat treatment temperature of the inorganic material layer 2 or the fluororesin film (surface layer) 5.

  Prior to the formation of the inorganic material layer, the substrate surface is degreased by high-temperature baking or solvent washing, and the maximum height Rz of the contour curve is 3 μm to remove the oxide film on the surface by sandblasting or the like and increase the adhesive force The surface is preferably roughened to 100 μm.

  The method for forming the inorganic material layer 2 is not particularly limited as long as the layer having the above-described properties can be formed. However, the spraying method can select a wide range of types of spraying materials, and the formed film is porous. It is preferable from the point which is not restrict | limited to the point which becomes, and also the kind of substrate, shape, and dimension. The spraying method is not particularly limited, and can be selected according to appropriate conditions such as arc spraying, flame spraying, HVOF (supersonic oxygen combustion) spraying, and plasma spraying. Of these, powder flame spraying is preferable from the viewpoint of adhesion to the base material and thermal spray material.

  The formed inorganic material layer 2 has a layer thickness of 10 μm to 300 μm, an arithmetic average height Ra of the contour curve of 2 μm to 25 μm, a Rockwell hardness of HRC30 or more, and fine pores on the surface. (Porous)

  Next, a fluororesin film (surface layer) 5 is formed on the inorganic material layer 2. Various methods can be used to form the fluororesin film 5 depending on the type, state, viscosity, etc. of the fluororesin of the resin. In the case of a dispersion, a dip coating method, a spray coating method, a brush coating, etc. In this case, an electrostatic powder coating method, a fluid dipping method, or the like is appropriate.

  The film thickness of the fluororesin film 5 may be selected as appropriate, but the arithmetic average height Ra of the contour curve of the inorganic material layer 2 is not reduced as much as possible. The film thickness of the fluororesin film 5 is preferably impregnated for a coating amount of 1 to 50 μm.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. In the examples of the present invention, the following evaluation tests (1) to (2) were performed on inventive examples 1 to 10 and comparative examples 1 to 11.

(1) Arithmetic mean height Ra of the contour curve of the surface layer:
JIS
The arithmetic average height Ra of the contour curve defined in B0601: 2001 was measured for the surface layer.

(2) Tape non-adhesion test:
Using a 25 mm wide Nitto tape-made gum tape, after sufficient gumming was applied, the force required to slowly peel the gum tape vertically was measured with a SIMPO Digital Force Gauge FGC-10. In the measurement, the maximum value when a 50 mm tape was peeled was taken as the measured value.

(Invention Example 1):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  An Ni—Cr self-fluxing alloy is sprayed onto this stainless steel plate with a powder flame spraying machine to a film thickness of about 100 μm, and an inorganic material layer having a Rockwell hardness HRC50 and an arithmetic average height Ra of 14.6 μm is obtained. It was.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Invention Example 2):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  An Ni—Cr self-fluxing alloy is sprayed onto this stainless steel plate with a powder flame spraying machine to a film thickness of about 100 μm, and an inorganic material layer having a Rockwell hardness HRC50 and an arithmetic average height Ra of 14.6 μm is obtained. It was.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 31% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Invention Example 3):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  A Ni—Cr self-fluxing alloy was sprayed onto this stainless steel plate with an HVOF spraying machine to a film thickness of about 100 μm, and an inorganic material layer having a Rockwell hardness HRC50 and an arithmetic average height Ra of 8.5 μm of the contour curve was obtained.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Invention Example 4):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a cross-linked fluororesin is applied to the film so as to have a film thickness of 10 μm to 20 μm by an electrostatic powder coating method. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Invention Example 5):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Invention Example 6):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Invention Example 7):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina having a large particle size.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Invention Example 8):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. On top of this, a tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 31% by weight of a crosslinked fluororesin is applied by an electrostatic powder coating method so as to have a film thickness of 10 μm to 20 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Invention Example 9):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 31% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Invention Example 10):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 31% by weight of a cross-linked fluororesin is applied to the film so as to have a film thickness of 60 μm to 90 μm by an electrostatic powder coating method. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Comparative Example 1):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  An Ni—Cr self-fluxing alloy is sprayed onto this stainless steel plate with a powder flame spraying machine to a film thickness of about 100 μm, and an inorganic material layer having a Rockwell hardness HRC50 and an arithmetic average height Ra of 14.6 μm is obtained. It was.

  A primer for fluororesin is applied by a spray method and baked at 360 ° C. for 60 minutes using an electric furnace. An aqueous dispersion paint composed of tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) and / or polytetrafluoroethylene (PTFE) is applied on this by a spray coating method, and using an electric furnace at 390 ° C. for 60 minutes. Melt baking was performed.

(Comparative Example 2):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  An Ni—Cr self-fluxing alloy is sprayed onto this stainless steel plate with a powder flame spraying machine to a film thickness of about 100 μm, and an inorganic material layer having a Rockwell hardness HRC50 and an arithmetic average height Ra of 14.6 μm is obtained. It was.

  A primer for fluororesin is applied by a spray method and baked at 360 ° C. for 60 minutes using an electric furnace. An aqueous dispersion paint composed of tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) was applied thereon by a spray coating method, and melt-baked at 400 ° C. for 60 minutes using an electric furnace. Further, an aqueous dispersion paint composed of tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) was applied thereon by a spray coating method and melt-baked at 360 ° C. for 60 minutes using an electric furnace.

(Comparative Example 3):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  An Ni—Cr self-fluxing alloy was sprayed on this stainless steel plate with an HVOF spraying machine to a film thickness of about 100 μm, and an inorganic material layer having a Rockwell hardness HRC50 and an arithmetic average height Ra of 8.2 μm of the contour curve was obtained.

  A primer for fluororesin is applied by a spray method and baked at 360 ° C. for 60 minutes using an electric furnace. An aqueous dispersion paint composed of tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) was applied thereon by a spray coating method, and melt-baked at 400 ° C. for 60 minutes using an electric furnace. Further, an aqueous dispersion paint composed of tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) was applied thereon by a spray coating method and melt-baked at 360 ° C. for 60 minutes using an electric furnace.

(Comparative Example 4):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  A Ni—Cr self-fluxing alloy was sprayed onto this stainless steel plate with an HVOF spraying machine to a film thickness of about 100 μm, and an inorganic material layer having a Rockwell hardness HRC50 and an arithmetic average height Ra of 8.5 μm of the contour curve was obtained.

  A primer for fluororesin is applied by a spray method and baked at 360 ° C. for 60 minutes using an electric furnace. An aqueous dispersion paint composed of tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) and / or polytetrafluoroethylene (PTFE) is applied on this by a spray coating method, and is used at 390 ° C. for 60 minutes using an electric furnace. Melt baking was performed.

(Comparative Example 5):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  Primer for fluororesin is applied by spray method and baked at 360 ° C for 60 minutes using an electric furnace, and water-based dispersion paint made of tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) is sprayed on it. And then baked at 400 ° C. for 60 minutes using an electric furnace. Further, an aqueous dispersion paint made of tetrafluoroethylene-perfluoroalkoxyethylene polymer (PFA) was applied thereon by a spray coating method, and melted and baked at 360 ° C. for 60 minutes using an electric furnace.

(Comparative Example 6):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate. Thereafter, the surface was roughened by blasting with alumina.

  A fluororesin primer is applied by a spray method and baked at 360 ° C. for 60 minutes using an electric furnace. From this, tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) and polytetrafluoroethylene (PTFE) are used. The resulting aqueous dispersion paint was applied by spray coating, and melt-baked at 390 ° C. for 60 minutes using an electric furnace.

(Comparative Example 7):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 4.25% by weight cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Then, using an electric furnace, melt baking was performed at 340 ° C. for 60 minutes.

(Comparative Example 8):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. On top of this, a tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 8.5% by weight of a crosslinked fluororesin is applied by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Then, using an electric furnace, melt baking was performed at 340 ° C. for 60 minutes.

(Comparative Example 9):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace. After this baking, the coating surface was polished with # 2000 file.

(Comparative Example 10):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. On top of this, a tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a crosslinked fluororesin is applied by an electrostatic powder coating method so as to have a film thickness of 60 μm to 90 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

(Comparative Example 11):
A stainless steel plate (SUS304) (thickness 2 mm × width 50 mm × length 100 mm) was degreased with acetone as a substrate.

  A primer for fluororesin was applied by a spray method and dried at 150 ° C. for 30 minutes using an electric furnace. A tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 40 μm. Melt baking was performed for 60 minutes at 340 ° C. using an electric furnace.

  Further, a tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) powder coating containing 17% by weight of a cross-linked fluororesin is coated thereon by an electrostatic powder coating method so as to have a film thickness of 30 μm to 50 μm. Then, using an electric furnace, melt baking was performed at 340 ° C. for 60 minutes. A coating layer having a total film thickness of 60 μm to 90 μm was obtained by the above two coating formations.

  Table 1 (Invention Example) and Table 2 (Comparative Example) show the evaluation results of (1) Ra of the surface layer and (2) tape non-adhesion test for Invention Examples 1 to 10 and Comparative Examples 1 to 11.

  As described above, Invention Examples 1 and 2 in which the fluororesin film containing the crosslinked fluororesin is applied to the inorganic material layer are excellent in tape non-adhesiveness. Moreover, if surface roughness is ensured by the blasting of the base material even if there is no inorganic material layer as in Invention Examples 6 and 7, the surface layer is formed with a fluororesin film containing a cross-linked fluororesin, thereby making the tape non-adhesive Can be improved. Further, it should be noted that, as in Examples 4, 5, 8, 9, and 10 of the present invention, there is no inorganic material layer, and even if the base material is not subjected to blasting treatment, 10% by weight of the cross-linked fluororesin is contained in the surface layer. If the surface layer thickness is not more than a predetermined value, the arithmetic average height of the contour curve of the surface layer can be 1.5 μm or more. In the present invention examples 4, 5, 8, 9, and 10, the adhesive strength of the tape non-adhesive test can be lowered at low cost by containing the cross-linked fluororesin in the surface layer in the above range. In particular, the inventive examples 8, 9, and 10 containing 31% by weight of a cross-linked fluororesin in the surface layer have the arithmetic average height of the contour curve of the surface layer even without an inorganic material layer and without blasting the substrate. It can be seen that excellent non-adhesiveness is exhibited at a surface layer thickness of 10 μm to 90 μm.

  On the other hand, in Comparative Examples 9, 10, and 11, even if the surface layer contains 17% by weight of the cross-linked fluororesin, the surface layer (upper layer) has a surface layer thickness of 30 μm to 90 μm when the surface roughness is not sufficient. The arithmetic average height of the contour curve cannot be 1.5 μm or more, and as a result, the tape non-adhesiveness becomes unsatisfactory. In Comparative Examples 7 and 8, in which the degree of unevenness of the base is not sufficient and the weight ratio of the cross-linked fluororesin in the surface layer is not high, tape non-adhesiveness is not preferable. Further, in Comparative Example 9 in which the surface of the fluororesin containing 17% by weight of the cross-linked fluororesin was file-polished, the non-adhesive performance was obviously deteriorated as compared with Invention Example 5 (without polishing).

  Further, in Examples 1 to 3 of the present invention, when the surface roughness is positively secured by the inorganic material layer and the surface layer sufficiently includes the cross-linked fluororesin, the example has been observed so far while the film is firmly retained. As much as possible, it is possible to obtain a coating layer having excellent tape non-adhesiveness.

  In the above-mentioned coating layer of the present invention, since silicone oil is not used, the silicone oil does not move to the pressure-sensitive adhesive that comes into contact with it, and the adhesiveness of the pressure-sensitive adhesive tape itself (product) is not lowered.

  From the above, by using the coating layer of the present invention, a conventional silicone oil coating method, a method of coating a silicone resin or fluororesin, or a substrate surface such as a roll is treated with thermal spraying or blasting. Compared with the non-adhesive coating method using these methods or a combination thereof, a highly durable non-adhesive coating layer free from silicone migration or the like can be obtained.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing which shows the coating layer in Embodiment 1 of this invention. It is sectional drawing which shows the coating layer in Embodiment 2 of this invention. It is sectional drawing which shows the coating layer in Embodiment 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Base material, 1a Rough surface layer of a base material, 2 Inorganic material layer, 3 Primer layer for fluororesins, 5 Surface layer.

Claims (10)

A coating layer covering a substrate,
A surface layer formed of a fluororesin layer containing 10% by weight to 50% by weight of a crosslinked fluororesin,
The coating layer whose arithmetic mean height Ra of the contour curve of the said surface layer is 1.5 micrometers-25 micrometers.   The coating layer according to claim 1, wherein the thickness of the surface layer is in the range of 5 μm to 300 μm.   The coating layer according to claim 1, wherein the surface layer is formed on the substrate.   The coating layer according to claim 3, wherein the arithmetic average height Ra of the contour curve of the substrate surface is 25 µm or less.   The coating layer of Claim 1 or 2 further provided with the inorganic material layer which is located between the said base material and the said surface layer, and whose arithmetic mean height Ra of the contour curve of the surface of the surface layer side is 25 micrometers or less.   The coating layer according to claim 6, wherein the inorganic material layer has a thickness of 10 μm to 300 μm.   The coating layer according to claim 5 or 6, wherein the inorganic material constituting the inorganic material layer is a self-fluxing alloy.   The coating layer according to claim 5, wherein ceramic particles having a particle size of 50 μm or less are contained in the inorganic material layer.   The coating layer according to any one of claims 1 to 8, wherein the surface layer further has an intermediate fluororesin layer at the bottom thereof. A method for forming a coating layer covering a substrate, comprising:
A method for forming a coating layer, wherein a surface layer having an arithmetic mean height Ra of a contour curve of 1.5 μm to 25 μm is formed of a fluororesin containing 10% by weight to 50% by weight of a crosslinked fluororesin.

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