JP2016007709A - Non-adhesive film structure and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-adhesive film structure that exhibits non-adhesiveness and excels in wear resistance as well as a method for producing the same.SOLUTION: A non-adhesive film structure 1 formed on a metal substrate 10 comprises an inorganic layer 2 formed by applying an inorganic coating 20 that includes at least an inorganic binder so as to cover the surface of the metal substrate 10. A surface layer part 3 of the inorganic layer 2 contains fluororesin particles 31 in an ununiformly dispersed manner. The fluororesin particles 31 are dispersed along a surface 2a of the inorganic layer 2. Specifically, the fluororesin particles 31 are unevenly distributed in the recess 4 on the surface 2a of the inorganic layer 2.

Description

  The present invention relates to a technique of a non-adhesive film structure and a manufacturing method thereof, and more particularly to a non-adhesive film structure formed on a metal substrate and a manufacturing method thereof.

  Conventionally, in high-temperature cooking equipment such as frying pans and microwave ovens, non-adhesive formed by applying fluororesin paint (top coating) to the cooking surface (metal substrate) to reduce scorching and improve cleaning performance etc. The structure of the non-adhesive film which has a layer is known. This type of non-adhesive layer has not only non-adhesive properties, but also low friction, chemical resistance, insulation, and other characteristics. It is used for molding dies such as rubber and resin, and conveyance rollers and guides constituting a production line.

  By the way, in the above-mentioned film structure, since the hardness of the non-adhesive layer formed by the fluororesin coating is low and easily damaged, for example, the surface of the metal substrate is subjected to surface treatment such as ceramic spraying, and then the fluororesin A coating structure with improved wear resistance has been proposed, such as applying a coating to form a non-adhesive layer, or applying a fluororesin coating containing ceramic powder to form a non-adhesive layer. Yes. However, in such a configuration, the adhesion between the undercoat layer (including the ceramic sprayed layer) and the non-adhesive layer is low, and the non-adhesive layer is exposed due to peeling of the non-adhesive layer and the non-adhesiveness and wear resistance are early. There is a problem that the durability is inferior.

  From this point of view, for example, as disclosed in Patent Document 1 and Patent Document 2, a ceramic layer obtained by applying a paint mainly composed of polycarbosilane containing a fluororesin on a metal substrate to be ceramicized; There has been proposed a coating structure having a non-adhesive layer formed by applying a fluororesin coating on a ceramic layer. Further, as disclosed in Patent Document 3, a ceramic layer obtained by applying a sol-gel coating containing inorganic oxide fine particles to be ceramicized, a non-adhesive layer formed by applying a fluororesin coating on the ceramic layer, and There has been proposed a coating structure comprising:

  In the conventional film structure disclosed in Patent Document 1 and Patent Document 2 described above, the fluorine resin component is certainly contained in the ceramic layer, so that the fluorine resin component and the fluorine resin component in the non-adhesive layer are included. Is mixed and melted to improve the adhesion between the two layers, and in the conventional film structure disclosed in Patent Document 3, inorganic oxide fine particles are contained in the ceramic layer, so that the inorganic exposed on the surface of the ceramic layer. Since the surface area is increased by the oxide fine particles and the adhesion to the non-adhesive layer is improved, delamination between the ceramic layer and the non-adhesive layer is prevented, and an improvement in durability is expected.

  However, in the conventional film structures disclosed in Patent Document 1 to Patent Document 3 described above, since the non-adhesive layer is formed from a fluororesin layer, the non-adhesive that the hardness is low and scratches or the like easily occur. The problem of wear resistance of the layer itself is still not solved. For this reason, in high-temperature cooking equipment having such a coating structure, the non-adhesiveness and wear resistance are reduced depending on the number of times of use and usage conditions. A film structure excellent in wear resistance is desired.

JP-A-3-32618 Japanese Patent Laid-Open No. 7-8387 JP-A-10-176277

  Accordingly, the present invention relates to a non-adhesive film structure and a method for producing the same, and solves the above-described conventional problems. The non-adhesive film structure having excellent wear resistance while exhibiting non-adhesiveness and a method for producing the same The purpose is to provide.

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
As a result of intensive studies in view of the above problems, the present inventors applied and formed an inorganic paint containing an inorganic binder and a fluororesin particle dispersion containing fluororesin particles, respectively, on the surface layer portion. It has been found that a ceramic layer containing fluororesin particles in a dispersed state can be formed, and a non-adhesive film structure and a method for producing the same that are excellent in wear resistance while exhibiting non-adhesiveness can be obtained. The present invention has been completed.

  That is, in claim 1, in the non-adhesive film structure formed on the metal base material, it is formed by applying an inorganic paint containing at least an inorganic binder so as to cover the surface of the metal base material. It consists of an inorganic layer, and the fluororesin particles are contained in a non-uniformly dispersed state in the surface layer portion of the inorganic layer.

  In the present invention, the fluororesin particles are dispersed along the surface of the inorganic layer.

  According to a third aspect of the present invention, the fluororesin particles are unevenly distributed in the recesses on the surface of the inorganic layer.

  5. The inorganic layer according to claim 4, wherein the inorganic layer is formed by applying a fluororesin particle dispersion liquid containing fluororesin particles on an inorganic paint containing an inorganic binder applied so as to cover the surface of the metal substrate. It is what is done.

  In the present invention, the fluororesin particles are PTFE particles.

  In the present invention, the inorganic paint contains an alkoxysilane compound as an inorganic binder.

  The method of manufacturing a non-adhesive film structure formed on a metal base material according to claim 7, wherein a step of applying an inorganic paint containing an inorganic binder so as to cover the surface of the metal base material, A step of applying a fluororesin particle dispersion containing fluororesin particles on an inorganic coating applied on a substrate; and firing a coating film comprising the inorganic coating and the fluororesin particle dispersion at the surface layer portion. And a step of forming an inorganic layer in which the fluororesin particles are dispersed non-uniformly.

  In claim 8, the firing temperature is a temperature lower than or near the melting point of the fluororesin particles.

  As an effect of the present invention, a non-adhesive film structure excellent in abrasion resistance can be obtained while exhibiting non-adhesiveness.

It is sectional drawing which showed the whole structure of the membrane | film | coat structure concerning one Example of this invention. It is sectional drawing explaining the manufacturing process of film structure. It is the flowchart explaining the manufacturing process of film structure. It is sectional drawing which represented typically the dispersion state of the fluororesin particle | grains in the recessed part of the surface of an inorganic layer. It is the SEM image and EDX spectrum of the whole cross section of a film structure. It is the SEM image and EDX spectrum of the cross section of the upper layer part of a film structure. It is the SEM image and EDX spectrum of the cross section of the lower part of a film structure. It is the SEM image and EDX spectrum of the surface of a film structure. It is an EDX spectrum other than (a) recessed part and (b) recessed part of the surface of a film structure.

  Next, modes for carrying out the invention will be described.

  As shown in FIG. 1, the film structure 1 of the present embodiment is composed of an inorganic layer 2 formed by applying an inorganic paint 20 containing at least an inorganic binder so as to cover the surface of the metal substrate 10, and the inorganic structure 2 In the surface layer portion 3 of the layer 2, the fluororesin particles 31 are contained in a non-uniformly dispersed state. Specifically, in the film structure 1 of the present embodiment, the surface of the metal material 10 is coated with an inorganic coating 20 containing an inorganic binder and a fluororesin particle dispersion 30 containing fluororesin particles 31 and fired. Thus, one layer of the inorganic layer 2 is obtained in which the fluororesin particles 31 are dispersed in the surface layer portion 3 in a non-uniform manner. Thus, the film structure 1 composed of the inorganic layer 2 contained in a state in which the fluororesin particles 31 are dispersed in the surface layer portion 3 in a non-uniform manner exhibits non-adhesiveness due to the fluororesin particles 31 of the surface layer portion 3. The ceramic part 21 made of ceramic has high hardness and excellent friction resistance.

<Metal base material>
The metal substrate 10 is made of various metal materials such as aluminum, aluminum alloy, zinc, zinc alloy, tin, tin alloy, etc., stainless steel, titanium, titanium alloy, zirconium, zirconium alloy, or the like, or silicon. A semi-metal material such as can be used.

<Inorganic paint>
Although the inorganic coating material 20 will not be specifically limited if a ceramic layer (ceramic part 21) is formed as the inorganic layer 2, A sol-gel coating material is used preferably. A sol-gel coating is a three-dimensional solution that contains a metal oxide as the main component by hydrolyzing and polycondensing a solution containing a metal alkoxide compound as an inorganic binder to change it from a sol to a solid gel. It is a paint that forms a film having a crosslinked matrix structure.

  Examples of the inorganic binder include those containing various metal alkoxide compounds of silicon (Si), aluminum (Al), titanium (Ti), and zirconium (Zr), and those containing water glass. Especially, as the inorganic coating material 20 of a present Example, a metal alkoxide compound is preferably used as an inorganic binder, and an alkoxysilane compound is more preferably used among them. This is because the alkoxysilane compound has a slow reaction rate of water decomposition / dehydration condensation reaction, and can easily form a stable uniform film.

As the alkoxysilane compound, a tetraalkoxysilane represented by a general formula Si (OR) ₄ (wherein R is an alkyl group having 1 to 5 carbon atoms), or a general formula R ¹ Si (OR ² ) ₃ (wherein R ¹ is an organic group having 1 to 8 carbon atoms, R ² is like organotrialkoxysilane represented by an alkyl group) having 1 to 4 carbon atoms. As the alkoxysilane compound, organotrialkoxysilane or tetraalkoxysilane may be used alone, or a mixture of organotrialkoxysilane and tetraalkoxysilane may be used.

As the tetraalkoxysilane, tetramethoxysilane [Si (OCH ₃ ) ₄ ] or tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] can be used. As the organotrialkoxysilane, methyltrimethoxysilane [CH ₃ Si (OCH ₃ ) ₃ ] or methyltriethoxysilane [CH ₃ Si (OC ₂ H ₅ ) ₃ ] can be used.

Examples of other metal alkoxide compounds include aluminum metal alkoxide compounds such as aluminum isopropoxide [Al (OCH (CH ₃ ) ₂ ) ₃ ], and titanium metal alkoxide compounds such as titanium tetraisopropoxide [ For example, a β-diketone derivative of zirconium isopropoxide can be used for Ti (OC ₃ H ₇ ) ₄ ] and the like and zirconium-based metal alkoxide compounds.

  In addition to the inorganic binder described above, the inorganic paint 20 includes a filler, an inorganic pigment, water, an anti-aging agent, an antiseptic, a softening agent, an ultraviolet absorber, an antioxidant, a light stabilizer, a heat stabilizer, Contains known ingredients such as antistatic agents. In particular, when an alkoxysilane compound (such as organotrialkoxysilane) is used as the inorganic binder, colloidal silica is preferably contained as the filler. By mix | blending colloidal silica, the generation | occurrence | production of the porosity and the crack of the inorganic layer 2 is prevented, and preparation of the target film thickness (10-40 micrometers) becomes easy.

  As a composition ratio of the inorganic coating material 20, for example, when an alkoxysilane compound (such as organotrialkoxysilane) is used as the inorganic binder, the alkoxysilane compound is 20 to 40 parts by weight with respect to 100 parts by weight of the inorganic coating material, And 20-40 weight part of colloidal silica is mix | blended. This is because if the amount of the alkoxysilane compound is 20 parts by weight or less, the hardness of the inorganic layer 2 decreases, and if it is 40 parts by weight or more, the inorganic coating gels at room temperature and storage stability decreases. Moreover, if the colloidal silica is 10 parts by weight, the flexibility of the inorganic layer 2 is lowered, and if it is 40 parts by weight or more, the adhesion between the inorganic layer 2 and the metal substrate 10 is lowered.

  As described above, in the film structure 1 of the present embodiment, the inorganic layer 2 is formed using the sol-gel paint as the inorganic paint 20, so that the inorganic layer 2 can be adhered and fixed to the surface of the metal substrate 10. . In addition, since the inorganic layer 2 is denser and has less pores than a plasma sprayed layer formed by conventional plasma spraying or the like, it is difficult for scorch or the like to penetrate in the depth direction of the coating, thereby suppressing scorching and stain contamination. it can.

  In this embodiment, as will be described later, in order to obtain the inorganic layer 2 containing the fluororesin particles 31 in the surface layer portion 3 in a non-uniformly dispersed state, the fluororesin is mainly formed on the inorganic paint 20. The method for forming the inorganic layer 2 by applying the fluororesin particle dispersion 30 containing the particles 31 will be described. As the inorganic coating material 20, a ceramic layer (ceramic part 21) is formed as the inorganic layer 2. For example, the fluororesin dispersion liquid 30 described later may be made unnecessary by mixing the fluororesin particles 31 in the inorganic paint 20.

<Fluorine resin particle dispersion>
Unlike the conventional fluororesin paint, the fluororesin particle dispersion 30 is not mixed with a binder resin, and a liquid material in which the fluororesin particles 31 are contained in a dispersed state (dispersion) in a dispersion medium is used.

  As the fluororesin particles 31, fully fluorinated resin particles; polytetrafluoroethylene (PTFE), partially fluorinated resin particles; polychlorotrifluoroethylene (PCTFE, CTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF) ), Fluorinated resin copolymer; tetrafluoroethylene / fluoro (alkyl vinyl ether) copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / ethylene copolymer (ETFE) One type selected from the group consisting of ethylene / chlorotrifluoroethylene copolymer (ECTFE), or a mixture of two or more types.

  As the fluororesin particles 31, PTFE particles, PFA particles, FEP particles, and mixtures thereof are preferably used, and in particular, those mainly composed of PTFE particles are more preferably used. This is because PTFE is particularly excellent in chemical resistance and heat resistance among fluororesins. Note that “mainly” means that it is contained at least 50% by volume or more, and resin including all PTFE is also included.

  As the dispersion medium, water, various organic solvents, or the like can be used. Examples of the organic solvent include alcohols such as ethanol, isopropyl alcohol and n-butanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as methyl acetate, ethyl acetate and butyl acetate, dimethylformamide and dimethyl sulfoxide. Polar solvents such as ethylene glycol monobutyl ether and diethylene glycol monobutyl ether, halogen solvents such as 1,1,1-trichloroethane and chloroform, cyclic ethers such as tetrahydrofuran and dioxane, benzene, toluene, xylene and the like One type selected from the group consisting of aromatics, etc., or a mixture of two or more types.

  In addition to the fluororesin particles 31 and the dispersion medium described above, the fluororesin particle dispersion 30 includes a dispersant, a colorant, an inorganic filler, an anti-aging agent, an antiseptic, a softener, an ultraviolet absorber, and an antioxidant. In addition, known compounding agents such as a light stabilizer, a heat stabilizer, and an antistatic agent may be contained. By containing at least a dispersant, sedimentation of the fluororesin particles 31 can be suppressed and dispersibility can be improved.

<Method for producing film>
As shown in FIGS. 2 and 3, the manufacturing method of the coating structure 1 includes a step S <b> 100 for performing a predetermined base treatment on the surface of the metal substrate 10, and an inorganic binder so as to cover the surface of the metal substrate 10. A step S110 of applying an inorganic paint 20 containing, a step S120 of applying a fluororesin particle dispersion 30 containing fluororesin particles 31 on the inorganic paint 20 applied on the metal substrate 10, an inorganic paint 20 and Step S130 for drying the coating film made of the fluororesin particle dispersion 30 and Step S140 for firing the coating film made of the inorganic coating 20 and the fluororesin particle dispersion 30 to form the inorganic layer 2 are included. Become.

  First, in step S100, a predetermined base treatment is performed on the surface of the metal substrate 10 (see FIG. 2A). The surface of the metal substrate 10 is degreased and cleaned by polishing with a metal brush or wiping with alcohol. Next, a blasting process such as sand blasting or shot blasting is performed to remove rust and deteriorated coating film present on the surface of the metal substrate 10 that has been degreased and cleaned, and rough surface processing having minute uneven portions is performed. The In addition, about the location which cannot perform blasting, mechanical cleansing with a power brush etc. may be performed.

  In steps S110 and S120, the inorganic coating 20 and the fluororesin particle dispersion 30 described above are applied in a layered manner on the surface of the metal substrate 10 subjected to the ground treatment (see FIGS. 2B and 2C). As a method for applying the paint, a known method such as brush coating or roller coating can be employed. In the manufacturing method of the film structure 1 of this embodiment, spray injection is preferably used. Since the sprayed sprayed paint is applied with pressure, it is possible to prevent the sprayed material from spreading in the form of a mist and to spread the paint uniformly on the surface of the metal base 10. .

  When the application is performed by spraying, the viscosity of the inorganic coating material 20 and the fluororesin particle dispersion 30 is adjusted, and in particular, the fired film thickness so that the inorganic coating material 20 and the fluororesin particle dispersion 30 are jetted well. Application conditions are set. For example, in step S110, the inorganic coating 20 is applied so that the fired film thickness is 5 to 40 μm, preferably 5 to 20 μm (see FIG. 2B). In step S120, the fired film thickness is 5 to 20 μm, The fluororesin particle dispersion liquid 30 is preferably applied so as to have a thickness of 5 to 15 μm (see FIG. 2C).

  In step S130, the coating film composed of the inorganic coating material 20 and the fluororesin particle dispersion 30 is preliminarily dried, and is preferably dried, for example, at a temperature of 90 to 150 ° C. for about 5 to 20 minutes.

  In step S140, the coating film made of the inorganic paint 20 and the fluororesin particle dispersion 30 is baked, and the inorganic paint 20 is converted into a ceramic by the firing, and the dispersion medium in the fluororesin particle dispersion 30 is removed. One layer of the inorganic layer 2 containing the fluororesin particles 31 in an unevenly dispersed state is formed in the surface layer portion 3 by, for example, partly fusing the fluororesin particles 31 (FIG. 2D). reference).

  As the firing temperature, for example, it is preferable to heat for about 10 to 30 minutes under a temperature condition of 250 to 330 ° C. which is a temperature lower than or near the melting point of the fluororesin particles 31. That is, for example, when PTFE particles are used as the fluororesin particles 31, since the melting point of PFTE is about 330 ° C., the firing temperature is 320 to 330 which is a temperature lower than or equal to the melting point. It adjusts so that it may become ° C. By setting the firing temperature to a temperature lower than or near the melting point of the fluororesin particles 31, some of the fluororesin particles 31 may be melted without melting the fluororesin particles 31 to form a fluororesin film. It is non-uniformly dispersed in the ceramic portion 21 of the inorganic layer 2 by forming a worn aggregate (lump).

  In addition, in the manufacturing method of the membrane | film | coat of a present Example, in order to obtain the inorganic layer 2 contained in the surface layer part 3 in the state by which the fluororesin particle 31 was disperse | distributed nonuniformly, mainly on the inorganic coating material 20 Although the method for forming the inorganic layer 2 by applying the fluororesin particle dispersion 30 containing the fluororesin particles 31 has been described, the method for producing the film is not limited to this, and the inorganic layer 2 is an inorganic material containing at least an inorganic binder. Any material can be used as long as it is formed by applying the paint 20. For example, a similar inorganic layer 2 may be obtained using a paint in which the fluororesin particles 31 are mixed in the inorganic paint 20.

<Coating structure>
As shown in FIG. 1, in the coating structure 1 of this example, the inorganic layer 2 formed by baking a coating film made of the inorganic coating 20 and the fluororesin particle dispersion 30 is an inorganic binder of the inorganic coating 20. As a result, the ceramic part 21 having a three-dimensional cross-linked matrix structure of metal oxide is formed. At the same time, part of the fluororesin particles 31 of the fluororesin particle dispersion 30 applied on the inorganic coating 20 are fused together to form an aggregate (lumb), etc. Dispersed unevenly inside. In particular, in the upper layer portion 3 of the inorganic layer 2, the fluororesin particles 31 rise due to the difference in specific gravity from the ceramic portion 21, and the density of the fluororesin particles 31 increases with the upper layer, and the ceramic portion 21 extends along the surface 2 a. The fluororesin particles 31 are dispersed in the glass.

  As shown in FIG. 4, in the coating structure 1 of the present embodiment, a plurality of recesses 4, 4... Are formed on the surface 2 a of the inorganic layer 2, and the fluororesin particles 31 are unevenly distributed in the recesses 4. . The concave portion 4 is a small depression having a substantially semicircular diameter of ˜20 μm that appears on the substantially flat surface 2a (see FIG. 8 and the like described later). The reason why the concave portion 4 is provided on the surface 2a of the inorganic layer 2 is not clear in detail, but by applying the fluororesin particle dispersion 30 to the surface of the inorganic paint 20, the inorganic paint 20 and the fluororesin particle dispersion 30 are applied. As a result of the influence of the presence of the fluororesin particles 31 present on the surface when the inorganic binder is ceramicized in the firing step, the recesses 4 are formed, and the fluororesin particles 31 are formed in the recesses 4 during the firing process. Is presumed to be distributed in an uneven distribution.

  Thus, the film structure 1 of this example is an inorganic film containing at least an inorganic binder so as to cover the surface of the metal substrate 10 in the non-adhesive film structure 1 formed on the metal substrate 10. It consists of the inorganic layer 2 formed by applying the paint 20, and the fluororesin particles 31 are contained in the surface layer portion 3 of the inorganic layer 2 in a non-uniformly dispersed state, so that the ceramic is formed on the surface 2 a of the inorganic layer 2. Since the fluororesin particles 31 are dispersed together with the portion 21, non-adhesiveness is exhibited by the fluororesin particles 31 in the surface layer portion 3, and the ceramic portion 21 can have friction resistance.

  In particular, in the film structure 1 of this example, the fluororesin particles 31 are unevenly distributed in the recesses 4 on the surface 2a of the inorganic layer 2, so that the surface 2a is made of a metal spatula or the like by using a high-temperature cooking appliance having the film structure 1. Even when rubbed, the fluororesin particles 31 are present in the recesses 4, so that the wear of the fluororesin particles 31 can be prevented, and the non-adhesiveness can be suppressed and the durability can be dramatically improved.

  Examples of the present invention and comparative examples will be described below. In addition, this invention is not restrict | limited by the Example shown below.

<Preparation of film structure>
An inorganic paint containing an alkoxysilane compound or the like as an inorganic binder at a composition ratio (% by weight) shown in Table 1, and PTFE or the like as a fluororesin particle at a composition ratio (% by weight) shown in Table 2. Using the fluororesin particle dispersion liquid, an inorganic paint is applied on a metal substrate to a fired film thickness of 20 μm, and a fluororesin particle dispersion liquid is applied to a fired film thickness of 10 μm, and pre-dried at 120 ° C. for 10 minutes. Then, baking was performed at 320 ° C. for 20 minutes to obtain a film structure composed of an inorganic layer in which a fluororesin was dispersed in the surface layer portion (Example 1).

  Moreover, as a comparative example, a film structure having a non-adhesive layer using a conventional fluororesin paint (Comparative Example 1) and a film structure having a ceramic layer using a conventional inorganic paint (Comparative Example 2) were prepared. . Specifically, for Comparative Example 1, a fired film thickness of 30 μm is formed on a metal substrate using a fluororesin paint (Daikin Industries, Ltd .: Polyflon EK-1909S201 (primer) and Polyflon EK-3798M201 (overcoat)). Each of the coatings was applied and pre-dried at 100 ° C. for 20 minutes, and then fired at 330 ° C. for 20 minutes to obtain a predetermined film structure. Moreover, about the comparative example 2, the inorganic coating material which contains an alkoxysilane compound etc. as an inorganic binder in the composition ratio (weight%) shown in Table 1 is used, and an inorganic coating material is baked on a base material. Each was coated to 25 μm, pre-dried at 90 ° C. for 20 minutes, and then fired at 300 ° C. for 20 minutes to obtain a predetermined film structure.

<Various film structure evaluation tests>
The following evaluation tests were performed on the film structure of this example (Example 1) and the film structure of Comparative Examples (Comparative Examples 1 and 2).

(A) Adhesion test It performed according to the method of the cross cut test in JIS K5400.

(B) Hardness test The hardness test was performed according to the method of the pencil scratch test in JIS K5400.

(C) Releasability test After dropping the mixture (soy sauce: sugar: egg = 1: 1: 1), heating at 250 ° C. for 30 minutes, washing with water and drying, the state of each film structure was visually observed. evaluated. In the evaluation, “◎” indicates that the mixture can be easily removed and there is no burnt stain, “○” indicates that the mixture can be easily removed, and if the burnt stain remains slightly, “△” indicates that the mixture is easily removed. When there were many spots that could be removed and burnt, “×” adopted a four-point evaluation method when the mixture could not be removed.

(D) Heat resistance test After heating at 250 ° C for 10 hours, the adhesion was confirmed according to the cross-cut test method in JIS K5400. In the evaluation, a case where no abnormality was observed was indicated as “◎”.

(E) Impact resistance test According to the weight drop resistance (falling ball type) test method in JIS K5600, a 300.0 ± 0.5 g weight was dropped from a height of 50 cm, and then the state of each coating structure Was visually evaluated. In the evaluation, a case where no abnormality was observed was indicated as “◎”.

(F) Boiling water resistance test After immersing in boiling water of 98 ° C or higher for 100 hours, water cooling and drying, the state of each film structure was visually evaluated. In the evaluation, a case where no abnormality was observed was indicated as “◎”.

(G) Acid resistance test According to the method of liquid resistance (immersion method) test in JIS K5600, after being immersed in a 5 w / v% sulfuric acid aqueous solution at room temperature for 16 hours, washed with water and dried, the state of each film structure was determined. Visual evaluation was performed. In the evaluation, a case where no abnormality was observed was indicated as “◎”.

(H) Alkali resistance test According to the method of the liquid resistance (immersion method) test in JIS K5600, the film structure was immersed in a 5 w / v% sodium hydroxide aqueous solution for 16 hours at room temperature, washed with water and dried. The state was evaluated visually. In the evaluation, the case where no abnormality was found was marked as “◎”.

  From the results of various evaluation tests shown in Table 3, the film structure of this example (Example 1) is non-adhesive using a conventional fluororesin paint compared to the conventional film structure (Comparative Examples 1 and 2). Exhibits releasability (non-adhesiveness) superior to a film structure having a layer, and has the same degree of hardness (abrasion resistance) as a film structure having a ceramic layer using a conventional inorganic paint Admitted. From this, it was confirmed that the film structure of the present example can be effectively used as a non-adhesive film having excellent friction resistance while exhibiting non-adhesiveness.

<Surface analysis of film structure>
First, an inorganic paint containing an alkoxysilane compound or the like as an inorganic binder at a composition ratio (% by weight) shown in Table 1, and PTFE or the like as a fluororesin particle at a composition ratio (% by weight) shown in Table 2. Using the fluororesin particle dispersion contained, an inorganic paint is applied onto a glass substrate so as to have a fired film thickness of 10 μm, and a fluororesin particle dispersion is applied to a fired film thickness of 10 μm, and at 120 ° C. for 10 minutes. After preliminary drying, the film was baked at 320 ° C. for 20 minutes to obtain a predetermined film structure. Then, the vertical cross section and the surface of the coating structure are observed by SEM using a scanning electron microscope (SEM) (manufactured by Hitachi High-Technologies: S-4800), and SEM is used using EDX (manufactured by Edax Japan: GenesisXM2). Under observation, vertical section and surface elemental analysis were performed.

  As shown in FIGS. 5 to 7, in the vertical cross section of the coating structure, innumerable particulate irregularities were observed from the SEM image, and F (fluorine) was detected in addition to Si (silicon) by the EDX measurement profile. Therefore (see FIG. 5), it was confirmed that the fluororesin particles were contained in the ceramic portion in a dispersed state. In particular, comparing the EDX measurement profiles of the upper layer section (see FIG. 6) and the lower section (see FIG. 7), F is detected in addition to Si in the upper layer section, while F is almost equal in the lower section. Not detected. As a result, the density of the fluororesin particles increases with the upper layer, and the fluororesin particles are dispersed in the ceramic part in the upper part of the inorganic layer, and the ceramic part occupies almost no fluororesin particles in the lower section. confirmed.

  Moreover, as shown in FIG.8 and FIG.9, in the surface of a film | membrane structure (inorganic layer), it was confirmed by the SEM image that the several recessed part with a caliber of -20-micrometer exists in the surface of an inorganic layer. In addition to Si, F was detected from the EDX measurement profile, and it was confirmed that the fluororesin particles were contained in a dispersed state in the ceramic portion along the surface of the coating structure. In addition, when the measurement profile of EDX around the concave portion (FIG. 9A) and the measurement profile of EDX other than the concave portion (FIG. 9B) are compared on the surface of the inorganic layer, F in addition to Si is formed around the concave portion. Although F was detected, F was hardly detected except for the concave portion. From this result, it was confirmed that the fluororesin particles were unevenly dispersed in the concave portions on the surface of the inorganic layer.

DESCRIPTION OF SYMBOLS 1 Film structure 2 Inorganic layer 2a Surface 3 Surface layer part 4 Recessed part 10 Metal base material 20 Inorganic coating material 21 Ceramic part 30 Fluorine resin particle dispersion 31 Fluorine resin particle

Claims (8)

In the non-adhesive film structure formed on the metal substrate,
It consists of an inorganic layer formed by applying an inorganic paint containing at least an inorganic binder so as to cover the surface of the metal substrate,
A non-adhesive film structure comprising fluorine resin particles dispersed in a surface layer portion of the inorganic layer in a non-uniform manner.   The non-adhesive film structure according to claim 1, wherein the fluororesin particles are dispersed along the surface of the inorganic layer.   The non-adhesive film structure according to claim 1 or 2, wherein the fluororesin particles are unevenly distributed in the concave portions on the surface of the inorganic layer.   The inorganic layer is formed by applying a fluororesin particle dispersion liquid containing fluororesin particles on an inorganic paint containing an inorganic binder applied so as to cover the surface of the metal substrate. The non-adhesive film structure according to claim 3.   The non-adhesive film structure according to claim 1, wherein the fluororesin particles are PTFE particles.   The non-adhesive film structure according to any one of claims 1 to 5, wherein the inorganic paint contains an alkoxysilane compound as an inorganic binder. In the method for producing a non-adhesive film structure formed on a metal substrate,
Applying an inorganic paint containing an inorganic binder so as to cover the surface of the metal substrate;
Applying a fluororesin particle dispersion containing fluororesin particles on the inorganic coating applied on the metal substrate;
Firing a coating film composed of the inorganic coating material and the fluororesin particle dispersion to form an inorganic layer in which the fluororesin particles are dispersed non-uniformly in a surface layer portion;
The manufacturing method of the non-adhesive film structure characterized by having.   The method for producing a non-adhesive film structure according to claim 7, wherein the firing temperature is a temperature lower than or near the melting point of the fluororesin particles.