JPWO2018070437A1 - Laminated body and method for producing the same - Google Patents

Abstract

A method for producing a laminate capable of forming a fluororesin layer that is simple and inexpensive to produce, has excellent adhesion to a substrate, and suppresses foaming and cracks, and a fluororesin that has excellent adhesion to the substrate A laminate comprising a layer is provided. An operation of electrostatic coating of a powder coating material containing a specific fluorine-containing copolymer and containing resin powder having an average particle size of 10 to 500 μm on a base material and firing is repeated twice or more, and a firing temperature of 350 ° C. or more and less than 380 ° C. A method for producing a laminate in which a fluororesin layer having a thickness of 50 μm or more is formed with a total firing time of 60 minutes or less. Moreover, the manufacturing method of the laminated body which provides the topcoat layer containing a 2nd fluorine-containing copolymer on the surface of the said resin layer. Furthermore, a stainless steel substrate and a fluororesin layer having a thickness of 50 μm or more on the surface of the substrate are provided, the resin layer contains 90% by mass or more of a specific fluorine-containing copolymer, and the resin layer and the substrate A laminate having a peel strength of 14 N / cm or more. And the laminated body which has the said topcoat layer on the surface of the said resin layer.

Description

  The present invention relates to a laminate and a method for producing the same.

  Fluoropolymers such as tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer (PFA) have a low coefficient of friction and excellent properties such as non-adhesiveness, chemical resistance, and heat resistance. It is widely used for surface processing of industrial products, kitchen appliances such as frying pans and pans, household items such as irons, electrical and industrial products, and mechanical and industrial products. For example, a method is known in which a powder coating material containing a fluoropolymer is applied to the surface of a substrate such as a frying pan and baked to form a fluororesin layer to obtain a laminate.

  However, the fluoropolymer is particularly poor in adhesion to a stainless steel substrate. Therefore, for the purpose of improving adhesion, it has been proposed to form a primer layer between the base material and the fluororesin layer. For example, a primer blended with a binder resin such as a heat-resistant resin and a fluorine-containing polymer is previously applied as a primer to form a primer layer, and the powder coating containing the fluorine-containing polymer on the primer layer The method of forming a fluororesin layer is mentioned (patent document 1). However, the method for forming the primer layer makes the manufacturing method complicated and disadvantageous in terms of cost.

  Incidentally, a resin powder made of a fluoropolymer having a specific functional group such as a carbonyl group-containing group is known as a resin powder having excellent adhesion to a substrate (Patent Document 2).

International Publication No. 2011/048965 International Publication No. 2016/017801

  However, when the present inventors examined, when the resin powder of patent document 2 is electrostatically coated on a base material as a powder coating material, and the baking operation is repeated twice or more to form a fluororesin layer having a thickness of 50 μm or more It has been found that foaming and cracks are likely to occur in the fluororesin layer.

  INDUSTRIAL APPLICABILITY The present invention provides a method for producing a laminate capable of forming a fluororesin layer that is simple and inexpensive to produce, has excellent adhesion to a substrate, and suppresses foaming and cracks, and adhesion to the substrate. A laminate comprising an excellent fluororesin layer is provided.

The present invention has the following configuration.
[1] An operation of electrostatically coating a powder coating on a base material and baking it is repeated twice or more to form a fluororesin layer having a thickness of 50 μm or more on the surface of the base material and fluorine A method for producing a laminate including a resin layer,
The powder paint includes a resin powder having an average particle size of 10 to 500 μm containing the following polymer A,
The manufacturing method of the said laminated body which sets baking temperature to 350 degreeC or more and less than 380 degreeC, and makes the total time set to the said baking temperature 60 minutes or less.
Polymer A: having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group, including a unit based on tetrafluoroethylene, and having a melting point of 260 to 320 ° C. , Fluorine-containing copolymer.

[2] The method for producing a laminate according to [1], wherein the polymer A is a fluorine-containing copolymer including a unit having the functional group.
[3] The polymer A is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having the functional group or a tetrafluoroethylene / hexafluoropropylene copolymer having the functional group. [1] Or the manufacturing method of the laminated body of [2]. [4] The method for producing a laminate according to any one of [1] to [3], wherein the thickness of the fluororesin layer is 100 μm or more.
[5] The method for producing a laminate according to any one of [1] to [4], wherein the substrate is a stainless steel substrate.

[6] A laminate is produced by the method of any one of [1] to [5], and a second fluorine-containing copolymer different from the polymer A is formed on the surface of the fluororesin layer of the obtained laminate. A method for producing a laminate, comprising forming a topcoat layer containing coalescence.
[7] The method for producing a laminate according to [6], wherein the topcoat layer is formed by powder coating using a resin powder containing the second fluorine-containing copolymer.
[8] The second fluorine-containing copolymer is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having no functional group, or a tetrafluoroethylene / hexafluoropropylene copolymer having no functional group. The manufacturing method of the laminated body of [6] or [7] which is united.

[9] The operation of electrostatic coating and baking of the powder coating material is repeated twice or more to form a fluororesin layer on the surface of the substrate, and a topcoat layer is formed on the fluororesin layer. A method for producing a laminate comprising a substrate and a fluororesin layer, characterized in that:
The total thickness of the fluororesin layer and the topcoat layer is 50 μm or more,
The powder coating material forming the fluororesin layer includes a resin powder having an average particle size of 10 to 500 μm and containing the following polymer A:
The powder coating material for forming the topcoat layer includes a resin powder having an average particle size of 10 to 500 μm including a second fluorine-containing copolymer different from the following polymer A,
The manufacturing method of the said laminated body which sets the calcination temperature at the time of forming a fluororesin layer and a topcoat layer to 330 degreeC or more and less than 380 degreeC, respectively, and makes the total time set to the said calcination temperature 60 minutes or less, respectively.
Polymer A: having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group, including a unit based on tetrafluoroethylene, and having a melting point of 260 to 320 ° C. , Fluorine-containing copolymer.
[10] The method for producing a laminate according to [9], wherein the polymer A is a fluorine-containing copolymer including a unit having the functional group.
[11] The polymer A is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having the functional group or a tetrafluoroethylene / hexafluoropropylene copolymer having the functional group. [9] Or the manufacturing method of the laminated body of [10].
[12] The second fluorine-containing copolymer is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having no functional group, or a tetrafluoroethylene / hexafluoropropylene copolymer having no functional group. The manufacturing method of the laminated body in any one of [9]-[11] which is a union.

[13] A stainless steel substrate and a fluororesin layer having a thickness of 50 μm or more formed on the substrate surface,
The fluororesin layer contains 90% by mass or more of the following polymer A ′,
A laminate having a peel strength between the fluororesin layer and the substrate of 14 N / cm or more.
Polymer A ′: a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer or a tetrafluoroethylene / hexafluoropropylene copolymer, and comprising a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group A fluorine-containing copolymer having at least one functional group selected from the group.
[14] A stainless steel base material, and a fluororesin layer and a topcoat layer formed on the surface of the base material,
The fluororesin layer contains 90% by mass or more of the following polymer A ′,
The topcoat layer includes a second fluorine-containing copolymer different from the following polymer A ′,
The total thickness of the fluororesin layer and the topcoat layer is 50 μm or more,
A laminate having a peel strength between the fluororesin layer and the substrate of 14 N / cm or more.
Polymer A ′: a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer or a tetrafluoroethylene / hexafluoropropylene copolymer, and comprising a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group A fluorine-containing copolymer having at least one functional group selected from the group.
[15] The second fluorine-containing copolymer is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having no functional group, or a tetrafluoroethylene / hexafluoropropylene copolymer having no functional group. The laminate of [14], which is a coalescence.

The manufacturing method of the laminated body of this invention is simple and low-cost, is excellent in adhesiveness with a base material, and a laminated body provided with the fluororesin layer by which foaming and the crack were suppressed is obtained.
The laminated body of this invention is equipped with the fluororesin layer excellent in adhesiveness with a base material.

The meanings of the following terms in this specification are as follows.
The “average particle diameter of the resin powder” is a volume-based cumulative 50% diameter (D50) obtained by a laser diffraction / scattering method. That is, the particle size distribution is measured by the laser diffraction / scattering method, the cumulative curve is obtained with the total volume of the group of particles being 100%, and the particle diameter is the point at which the cumulative volume is 50% on the cumulative curve.
The “melt flow rate” is a melt mass flow rate (MFR) defined in JIS K 7210: 1999 (ISO 1133: 1997).
The “unit” in the polymer means an atomic group derived from one monomer molecule formed by polymerization of the monomer. The unit may be an atomic group directly formed by a polymerization reaction, or an atomic group in which a part of the atomic group is converted into another structure by treating a polymer obtained by the polymerization reaction. Also good.
“(Meth) acrylate” is a general term for acrylate and methacrylate.

[Manufacturing method of laminate]
  According to a first aspect of the present invention, an operation of electrostatic coating and baking a powder coating material on a base material is repeated twice or more to form a fluororesin layer having a thickness of 50 μm or more on the surface of the base material. And a laminate manufacturing method for obtaining a laminate comprising a fluororesin layer.
  When the operation of electrostatic coating and baking is repeated twice or more, the powder paint in each operation may be the same or may be a different powder paint within the scope of the first aspect of the present invention. . For example, both are polymers A but different polymers (for example, polymer A described later)¹And polymer A ²) May be used to produce a laminate.
  A known method can be adopted as a method of electrostatically coating the powder coating material.

A known method can be adopted as the firing method.
The firing temperature is 350 ° C. or higher and lower than 380 ° C. When the firing temperature is 350 ° C. or higher, the adhesion between the formed fluororesin layer and the substrate is excellent. If a calcination temperature is less than 380 degreeC, it can suppress that a foaming and a crack arise in a fluororesin layer, and the laminated body excellent in the external appearance will be obtained. The firing temperature is preferably 350 to 375 ° C, and more preferably 350 to 370 ° C.
The firing temperature of each firing in two or more firings may be a different temperature or the same temperature.

  When firing twice or more, the total time (hereinafter also referred to as “total firing time”) to be placed at the firing temperature is 60 minutes or less, preferably 3 to 60 minutes, more preferably 4 to 60 minutes. Preferably, 5 to 45 minutes are more preferable, and 10 to 30 minutes are particularly preferable. If the total firing time is equal to or less than the upper limit of the above range, foaming and cracking can be suppressed in the fluororesin layer, and a laminate excellent in appearance can be obtained. When the total firing time is equal to or greater than the lower limit of the above range, the adhesion between the formed fluororesin layer and the substrate is excellent.

The firing time for each firing is preferably 1 to 20 minutes, and more preferably 1 to 15 minutes. When the firing time of each firing is equal to or greater than the lower limit of the above range, the resin is sufficiently melted and the surface smoothness is excellent. If the firing time of each firing is not more than the upper limit of the above range, foaming and cracks tend to be suppressed.
The firing time of each firing in two or more firings may be different or the same.

  The number of repetitions of the operation of electrostatic coating and baking may be appropriately set according to the thickness of the fluororesin layer to be formed within a range where the total baking time is 60 minutes or less, preferably 2 to 15 times. 10 times is more preferable.

  The lower limit of the thickness of the fluororesin layer to be formed is 50 μm, and 100 μm is preferable from the viewpoint of process shortening. The upper limit of the thickness of the fluororesin layer is preferably 750 μm and more preferably 500 μm from the viewpoint of improving chemical resistance.

The powder coating contains a resin powder containing the polymer A and having an average particle size of 10 to 500 μm.
The polymer A has at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group (hereinafter also referred to as “functional group (i)”), and tetrafluoro. It is a fluorine-containing copolymer containing a unit based on ethylene and having a melting point of 260 to 320 ° C.
Hereinafter, tetrafluoroethylene is referred to as “TFE”, and “unit based on TFE” is also referred to as “TFE unit”.

Since the polymer A is a polymer having a melting point, it is not a TFE homopolymer but a copolymer containing units based on monomers other than TFE. The units based on monomers other than TFE contained in the polymer A are not limited to one type, and may be two or more types. Examples of units based on monomers other than TFE include units based on fluorine-containing monomers other than TFE and units based on monomers having no fluorine atom. Further, the functional group (i) may be present in a unit contained in the polymer A, or may be present in a terminal group present at the terminal of the main chain of the polymer A.
The functional group (i) is preferably present in a unit contained in the polymer A. The unit having the functional group (i) may be either a unit based on a fluorine-containing monomer other than TFE or a unit based on a monomer having no fluorine atom, but a monomer having no fluorine atom Preferably, the unit is based on
When the functional group (i) is present in the terminal group present at the end of the main chain of the polymer A, the terminal group having the functional group (i) is used as the polymerization start used in the production of the polymer A. It is a terminal group derived from an agent or a chain transfer agent. The polymer A may include both a unit having the functional group (i) and a terminal group having the functional group (i).
Hereinafter, “unit having functional group (i)” is also referred to as “unit (1)”.

It is preferable that the polymer A contains a unit (excluding the unit (1)) based on a fluorine-containing monomer other than TFE as a unit other than the TFE unit. As a unit based on a fluorine-containing monomer other than TFE, a unit based on perfluoro (alkyl vinyl ether) and a unit based on hexafluoropropylene are preferable.
Hereinafter, “perfluoro (alkyl vinyl ether)” is also referred to as “PAVE”, and “unit based on PAVE” is referred to as “PAVE unit”. Similarly, “hexafluoropropylene” is also referred to as “HFP”, and “unit based on HFP” is also referred to as “HFP unit”. Hereinafter, the PAVE unit and the HFP unit are also collectively referred to as “unit (3)”.
When the polymer A contains the TFE unit and the unit (3) and the content ratio of both is appropriately adjusted, the polymer A tends to be a fluoropolymer having the melting point. As will be described later, the physical properties such as the melting point and melt flow rate (MFR) of the polymer A are hardly affected by the presence or absence of the unit (1) or the presence or absence of the terminal functional group (i). The ratio is adjusted according to the relative ratio and molecular weight between the TFE unit and the unit (3). The polymer A containing a unit (3) may contain both a PAVE unit and a HFP unit as a unit (3).

The polymer A may contain units other than the unit (3) (excluding the unit (1)) as units other than the TFE unit. Hereinafter, units other than the unit (1), the TFE unit and the unit (3) are also referred to as “unit (4)”. Examples of the monomer forming the unit (4) include fluorine-containing monomers other than PAVE and HFP, monomers having no fluorine atom, and the like. The polymer A may be a copolymer containing at least one unit (4) and a TFE unit.
As the copolymer containing at least one kind of unit (4) and TFE unit, a copolymer containing TFE unit, unit (3) and unit (4), and unit (1), TFE unit and unit ( A copolymer comprising 3) and units (4) is preferred.

The functional group (i) is a functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group, and the polymer A may have two or more of these functional groups. . The functional group (i) is preferably a carbonyl group-containing group.
The carbonyl group-containing group is not particularly limited as long as it is a group having a carbonyl group in the structure. For example, a group having a carbonyl group between carbon atoms of a hydrocarbon group, a carbonate group, a carboxy group, a haloformyl group. , Alkoxycarbonyl groups, acid anhydride residues, polyfluoroalkoxycarbonyl groups, fatty acid residues and the like. Among these, from the viewpoint of improving adhesion to the substrate, from a group having a carbonyl group between carbon atoms of a hydrocarbon group, a carbonate group, a carboxy group, a haloformyl group, an alkoxycarbonyl group, and an acid anhydride residue. A group selected from the group consisting of carboxy group and acid anhydride residue is more preferable.

Examples of the hydrocarbon group in the group having a carbonyl group between carbon atoms of the hydrocarbon group include alkylene groups having 2 to 8 carbon atoms. In addition, the carbon atom number of this alkylene group is the number of carbon atoms of parts other than the carbonyl group in this alkylene group. The alkylene group may be linear or branched.
The haloformyl group is a group represented by —C (═O) —X (where X is a halogen atom). Examples of the halogen atom in the haloformyl group include a fluorine atom and a chlorine atom, and a fluorine atom is preferable. That is, the haloformyl group is preferably a fluoroformyl group (also referred to as a carbonyl fluoride group).
The alkoxy group in the alkoxycarbonyl group may be linear or branched. As this alkoxy group, a C1-C8 alkoxy group is preferable, and a methoxy group or an ethoxy group is especially preferable.

The unit (1) is preferably a unit based on a monomer having a functional group (i) (hereinafter also referred to as “monomer (m1)”). The functional group (i) possessed by the monomer (m1) may be one or two or more. When the monomer (m1) has two or more functional groups (i), these functional groups (i) may be the same or different.
The monomer (m1) is preferably a compound having one functional group (i) and one polymerizable double bond.

Among the monomers (m1), examples of the monomer having a carbonyl group-containing group include a cyclic hydrocarbon compound having an acid anhydride residue and a polymerizable unsaturated bond (hereinafter referred to as “monomer (m11)”. ) ”), A monomer having a carboxy group (hereinafter also referred to as“ monomer (m12) ”), vinyl ester, (meth) acrylate, CF ₂ = CFOR ^f1 COOX ¹ (where R ^f1 is And a perfluoroalkylene group having 1 to 10 carbon atoms which may have an etheric oxygen atom, and X ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms).

As a monomer (m11), the acid anhydride etc. of unsaturated dicarboxylic acid are mentioned, for example. Examples of the acid anhydride of the unsaturated dicarboxylic acid include itaconic anhydride (hereinafter also referred to as “IAH”), citraconic anhydride (hereinafter also referred to as “CAH”), and 5-norbornene-2,3-dicarboxylic acid. Examples thereof include acid anhydrides (other names: anhydrous hymic acid, hereinafter also referred to as “NAH”), maleic anhydride, and the like.
Examples of the monomer (m12) include unsaturated dicarboxylic acids such as itaconic acid, citraconic acid, 5-norbornene-2,3-dicarboxylic acid and maleic acid; unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; Is mentioned.
Examples of the vinyl ester include vinyl acetate, vinyl chloroacetate, vinyl butanoate, vinyl pivalate, vinyl benzoate, vinyl crotonate, and the like.
Examples of (meth) acrylates include (polyfluoroalkyl) acrylate and (polyfluoroalkyl) methacrylate.

Examples of the monomer having a hydroxy group include vinyl esters, vinyl ethers, allyl ethers, (meth) acrylate compounds, etc., and compounds having one or more hydroxy groups at the terminal or side chain, crotonic acid Examples include crotonic acid-modified compounds such as hydroxyethyl, allyl alcohol, and the like.
Examples of the monomer having an epoxy group include unsaturated glycidyl ethers (for example, allyl glycidyl ether, 2-methylallyl glycidyl ether, vinyl glycidyl ether, etc.), unsaturated glycidyl esters (for example, glycidyl acrylate, Glycidyl methacrylate, etc.).
Examples of the monomer having an isocyanate group include 2- (meth) acryloyloxyethyl isocyanate, 2- (2- (meth) acryloyloxyethoxy) ethyl isocyanate, 1,1-bis ((meth) acryloyloxymethyl). Examples include ethyl isocyanate.

A monomer (m1) may be used individually by 1 type, and may use 2 or more types together.
The unit (1) preferably has at least a carbonyl group-containing group as the functional group (i) from the viewpoint of improving the adhesion to the substrate. As the monomer (m1), a monomer having a carbonyl group-containing group is preferable.

  As the monomer having a carbonyl group-containing group, the monomer (m11) is preferable from the viewpoint of improving thermal stability and adhesion to the substrate. Among these, a monomer selected from the group consisting of IAH, CAH, and NAH is particularly preferable. When at least one selected from the group consisting of IAH, CAH, and NAH is used, a special polymerization method required when maleic anhydride is used (see JP-A No. 11-193132) can be used. A fluorine-containing copolymer having an acid anhydride residue can be easily produced. Among IAH, CAH, and NAH, NAH is preferable because it has better adhesion to the substrate.

The unit (3) is a PAVE unit or an HFP unit.
Examples of PAVE include CF ₂ = CFOR ^f2 (where R ^f2 is a C 1-10 perfluoroalkyl group which may have an etheric oxygen atom). The perfluoroalkyl group for R ^f2 may be linear or branched. R ^f2 preferably has 1 to 3 carbon atoms.
As CF ₂ = CFOR ^f2 , CF ₂ = CFOCF ₃ , CF ₂ = CFOCF ₂ CF ₃ , CF ₂ = CFOCF ₂ CF ₂ CF ₃ (hereinafter also referred to as “PPVE”), CF ₂ = CFOCF ₂ CF ₂ CF ₂ CF ₃ , CF ₂ ═CFO (CF ₂ ) ₈ F and the like, and PPVE is preferable.
PAVE may be used individually by 1 type and may use 2 or more types together.

The monomer forming the unit (4) is a monomer other than the monomer (m1), TFE, PAVE, and HFP.
As the monomer forming the unit (4), the fluorine-containing monomer (hereinafter also referred to as “monomer (m41)”), the monomer having no fluorine atom (hereinafter referred to as “monomer”). Body (m42) ").

As the monomer (m41), a fluorine-containing compound having one polymerizable double bond is preferable. For example, vinyl fluoride, vinylidene fluoride (hereinafter also referred to as “VdF”), trifluoroethylene, chlorotrimethyl Fluoroolefin such as fluoroethylene (hereinafter also referred to as “CTFE”) (excluding TFE and HFP), CF ₂ = CFOR ^f3 SO ₂ X ³ (where R ^f3 has 1 to 10 carbon atoms) A perfluoroalkylene group or a C 2-10 perfluoroalkylene group having an etheric oxygen atom, and X ³ is a halogen atom or a hydroxy group.), CF ₂ ═CF (CF ₂ ) _p OCF═CF ₂ (Here, p is 1 or ^{_{2.), CH 2 = CX}} 4 (CF 2) q X 5 ( however, ^{X 4} is hydrogen Hara Or a fluorine atom, q is an integer of 2 to 10, ^{X 5} is a hydrogen atom or a fluorine atom.), Perfluoro (2-methylene-4-methyl-1,3-dioxolane) and the like. These may be used alone or in combination of two or more.

As the monomer (m41), a monomer selected from the group consisting of VdF, CTFE and CH ₂ ═CX ⁴ (CF ₂ ) _q X ⁵ is preferable.
As CH ₂ = CX ⁴ (CF ₂ ) _q X ⁵ , CH ₂ = CH (CF ₂ ) ₂ F, CH ₂ = CH (CF ₂ ) ₃ F, CH ₂ = CH (CF ₂ ) ₄ F, CH ₂ ═CF (CF ₂ ) ₃ H, CH ₂ ═CF (CF ₂ ) ₄ H, and the like, and CH ₂ ═CH (CF ₂ ) ₄ F and CH ₂ ═CH (CF ₂ ) ₂ F are preferable.

The monomer (m42) is preferably a compound having one polymerizable double bond and not having a fluorine atom, and examples thereof include olefins having 3 or less carbon atoms such as ethylene and propylene. These may be used alone or in combination of two or more.
As the monomer (m42), ethylene and propylene are preferable, and ethylene is particularly preferable.

  The monomer which forms a unit (4) may be used individually by 1 type, and may use 2 or more types together. When using 2 or more types together, 2 or more types of monomers (m41) may be used together, 2 or more types of monomers (m42) may be used together, and 1 or more types of monomers ( m41) and one or more monomers (m42) may be used in combination.

As the polymer A, a fluorine-containing copolymer containing the unit (1), the TFE unit and the PAVE unit (hereinafter, also referred to as “polymer A ¹ ”), the unit (1), the TFE unit and the HFP unit. And a fluorine-containing copolymer (hereinafter, also referred to as “polymer A ² ”) is preferable, and polymer A ¹ is particularly preferable. Hereinafter, these fluorine-containing copolymers will be described in detail.

The polymer ^{A 1,} the unit (1), and TFE units, and a PAVE units, the proportion of the unit (1) to the sum of all units is 0.01 to 3 mol%, the proportion of TFE units A fluorine-containing copolymer having 90 to 99.89 mol% and a PAVE unit ratio of 0.1 to 9.99 mol% is preferable.

The polymer A ¹ may further contain at least one of an HFP unit and a unit (4) as necessary. The polymer A ¹ may be composed of a unit (1), a TFE unit, and a PAVE unit, or may be composed of a unit (1), a TFE unit, a PAVE unit, and an HFP unit, and the unit (1) and a TFE unit. And PAVE unit and unit (4), or unit (1), TFE unit, PAVE unit, HFP unit and unit (4).

The polymer A ^1, the units based on a monomer having a carbonyl group-containing group, a TFE unit, a copolymer is preferable which includes a PAVE units, and units derived from monomer (m11), a TFE unit A copolymer containing PAVE units is particularly preferred. Specific examples of preferred polymer ^{A 1,} NAH / TFE / PPVE copolymer, IAH / TFE / PPVE copolymer, CAH / TFE / PPVE copolymer and the like.

Polymer A ¹ may have a functional group (i) as a main chain terminal groups. The functional group (i) as the main chain terminal group is preferably an alkoxycarbonyl group, a carbonate group, a carboxy group, a fluoroformyl group, an acid anhydride residue, or a hydroxy group. These functional groups are used in the production of polymer A ^1, the radical polymerization initiator can be introduced by suitably selecting the chain transfer agent and the like.

If the ratio of the unit (1) is equal to or higher than the lower limit of the above range, a resin powder having a large bulk density can be easily obtained, and the adhesion between the fluororesin layer and the substrate (metal or the like) is excellent. If the ratio of the unit (1) is not more than the upper limit of the above range, the heat resistance and color tone of the polymer A ¹ are good.
The proportion of the unit (1) is more preferably 0.03 to 2 mol%, particularly preferably 0.05 to 1 mol%.

  If the ratio of the TFE unit is not less than the lower limit of the range, the polymer A¹Has excellent heat resistance and chemical resistance. If the proportion of TFE units is less than or equal to the upper limit of the above range, the polymer A ¹Is excellent in stress crack resistance.
  The proportion of TFE units is more preferably 95 to 99.47 mol%, particularly preferably 96 to 98.95 mol%.

If the ratio of the PAVE unit is within the above range, the polymer A ¹ is excellent in moldability.
The proportion of the PAVE unit is more preferably 0.5 to 9.97 mol%, and particularly preferably 1 to 9.95 mol%.

The ratio of the total of the units (1), TFE units and PAVE units to the total of all units in the polymer A ¹ is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 98 mol% or more. . The upper limit of this ratio is not specifically limited, 100 mol% may be sufficient.

The ratio of each unit in the polymer A ¹ can be measured by NMR analysis such as fusion nuclear magnetic resonance (NMR) analysis, fluorine content analysis, infrared absorption spectrum analysis, or the like. For example, as described in Japanese Patent Application Laid-Open No. 2007-314720, the ratio (mol%) of the unit (1) in all units constituting the polymer A ¹ is determined using a method such as infrared absorption spectrum analysis. be able to.

Polymer ^{A 2} is a unit (1), and TFE units, and a HFP unit, the proportion of the unit (1) to the sum of all units is 0.01 to 3 mol%, the proportion of TFE units is 90 ～99.89 the mole%, the copolymer ratio of the HFP units is from 0.1 to 9.99 mol% (provided that the polymer ^{a 1} is excluded.) are preferred.

The polymer A ² may further include at least one of a PAVE unit and a unit (4) as necessary. The polymer A ² may be composed of a unit (1), a TFE unit and an HFP unit, and is composed of a unit (1), a TFE unit, an HFP unit and a PAVE unit (however, the polymer A ¹ is excluded). Or units (1), TFE units, HFP units, and units (4), or units (1), TFE units, HFP units, PAVE units, and units (4). , polymer ^{a 1} is excluded.) may be used.

The polymer A ^2, and units based on a monomer having a carbonyl group-containing group, a TFE unit, a copolymer is preferable which includes a HFP unit, and units derived from monomer (m11), a TFE unit And a copolymer containing an HFP unit is particularly preferred. Specific examples of preferred polymer ^{A 2,} NAH / TFE / HFP copolymer, IAH / TFE / HFP copolymer, CAH / TFE / HFP copolymer and the like.

Polymer A ² may have a functional group (i) as a main chain terminal groups. Preferred functional groups as the main chain end groups (i), be the same as those mentioned in Polymer A ^1.

If the ratio of the unit (1) is equal to or more than the lower limit of the above range, a resin powder having a large bulk density can be easily obtained, and the adhesion between the fluororesin layer and the substrate (metal or the like) is excellent. If the ratio of the unit (1) is not more than the upper limit of the above range, the heat resistance and color tone of the polymer A ² are good.
As for the ratio of a unit (1), 0.02-2 mol% is more preferable, and 0.05-1.5 mol% is especially preferable.

  If the ratio of the TFE unit is not less than the lower limit of the range, the polymer A²Has excellent heat resistance and chemical resistance. If the proportion of TFE units is less than or equal to the upper limit of the above range, the polymer A ²Is excellent in stress crack resistance.
  The proportion of TFE units is preferably 91 to 98 mol%, particularly preferably 92 to 96 mol%.

About the ratio of the said HFP unit, if it is in the range of the said range, it is excellent in peeling strength.
The proportion of HFP units is more preferably 1-9 mol%, particularly preferably 2-8 mol%.

The ratio of the total of the units (1), TFE units, and HFP units to the total of all units in the polymer A ² is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 98 mol% or more. . The upper limit of this ratio is not specifically limited, 100 mol% may be sufficient.

The melting point of the polymer A is 260 to 320 ° C, preferably 280 to 320 ° C, more preferably 295 to 315 ° C, and further preferably 295 to 310 ° C. If the melting point of the polymer A is not less than the lower limit of the above range, the heat resistance is excellent. If the melting point of the polymer A is not more than the upper limit of the above range, the balance between heat resistance and workability is excellent.
In addition, the melting point of the polymer A can be adjusted by the type and content ratio of the units constituting the polymer A, the molecular weight, and the like. For example, the melting point tends to increase as the proportion of TFE units increases.

The melt flow rate (MFR) of the polymer A is preferably 0.1 to 1000 g / 10 minutes, more preferably 0.5 to 100 g / 10 minutes, still more preferably 1 to 30 g / 10 minutes, and 5 to 20 g / 10. Minutes are particularly preferred. If MFR is not less than the lower limit of the above range, a layer having excellent processability and excellent flatness can be formed. When the MFR is not more than the upper limit of the above range, the polymer A is excellent in mechanical strength, and the fluororesin layer is excellent in mechanical strength.
The MFR is a measure of the molecular weight of the polymer A. When the MFR is large, the molecular weight is small, and when the MFR is small, the molecular weight is large. The molecular weight of the polymer A, and thus the MFR, can be adjusted by the production conditions of the polymer A. For example, if the polymerization time is shortened during polymerization of the monomer, the MFR tends to increase.

  The polymer A can be produced by a conventional method. Examples of the method for producing the polymer A include the methods (α) to (γ) described in [0053] to [0060] of International Publication No. 2016/017801.

The resin powder may contain a fluorine-containing polymer other than the polymer A, an aromatic polyester, a polyamideimide, a thermoplastic polyimide, or the like as long as the effects of the present invention are not impaired.
The ratio of the polymer A to the total amount of the resin powder is preferably 80% by mass or more, more preferably 85% by mass or more, further preferably 90% by mass or more, and particularly preferably 100% by mass.

  The average particle diameter of the resin powder is 10 to 500 μm, preferably 15 to 400 μm, and more preferably 20 to 300 μm. If the average particle size of the resin powder is equal to or greater than the lower limit of the above range, it is difficult to entrain air during electrostatic coating. If the average particle diameter of the resin powder is not more than the upper limit of the above range, the fluororesin layer can be thinned.

The powder coating material may contain components other than the resin powder as necessary. Examples of other components include pigments, carbon fibers, and graphite.
90 mass% or more is preferable and, as for content of the resin powder in a powder coating material, 95 mass% or more is more preferable. The upper limit of the content of the resin powder is 100% by mass.

The substrate is not particularly limited, and examples thereof include household items such as frying pans, pans, and irons, and factory piping.
The material of the substrate is not particularly limited, and examples thereof include metals such as stainless steel and iron, resins, glass, ceramics, and the like. The manufacturing method of the laminated body of this invention is especially effective in the case of the base material made from stainless steel with which it is difficult to ensure the adhesiveness of a base material and a fluororesin layer.
Moreover, you may use metal foil as a base material. Examples of the metal in the metal foil include copper, iron, aluminum, and stainless steel, and copper is particularly preferable.
In addition, the fluororesin layer can be formed by the production method of the present invention on a bendable metal substrate having a thickness of about 0.3 to 0.5 mm, which is thicker than the metal foil.

  According to the manufacturing method of the laminated body of the 1st aspect of this invention demonstrated above, the baking temperature of two or more baking is used using the powder coating material containing the polymer powder containing the polymer A and a specific average particle diameter. And by controlling the total time within a specific range, it is possible to produce a laminate comprising a fluororesin layer that is excellent in adhesion to the substrate and in which foaming and cracks are suppressed. Moreover, since the manufacturing method of the laminated body of this invention does not form a primer layer, manufacture is simple and it is low-cost.

The second aspect of the present invention is the second fluorine-containing copolymer different from the polymer A on the surface of the fluororesin layer of the laminate produced by the production method according to the first aspect of the present invention. A method for producing a laminate, comprising forming a topcoat layer containing
The second fluorine-containing copolymer is a fluorine-containing copolymer in the same category as the polymer A (hereinafter also referred to as “polymer B”) except that the functional group (i) is not included. Is preferred. As the polymer B, a copolymer containing TFE units and PAVE units and a copolymer containing TFE units and HFP units are preferable, and a copolymer containing TFE units and PAVE units is particularly preferable. The content ratio of each unit in these copolymers is preferably the content ratio of each unit when the content ratio of the unit (1) in the polymer A is 0.
The second fluorine-containing copolymer is not limited to the polymer B, and various heat-meltable fluorine-containing copolymers can be used.
Although the thickness of a topcoat layer is not specifically limited, 10 micrometers or more are preferable and 30 micrometers or more are preferable. Further, the total thickness of the fluororesin layer and the topcoat layer is preferably 750 μm or less, and more preferably 500 μm or less.
By providing the top coat layer, the non-adhesiveness of the resin layer surface is improved, and chemical properties such as chemical resistance are improved.

  The topcoat layer is preferably formed by a coating method using a powder paint containing the polymer B, and particularly preferably formed by a method in which an operation of electrostatic coating and baking is repeated one or more times. It is preferable that the powder coating containing the polymer B and the operation of baking by electrostatic coating are the same as in the first aspect of the present invention. For example, the powder coating contains resin powder having an average particle diameter of 10 to 500 μm containing the polymer B, and the baking temperature is 330 ° C. or higher and lower than 380 ° C., preferably 350 ° C. or higher and lower than 380 ° C. Is preferably 60 minutes or less. Thereby, after forming a fluororesin layer by a 1st aspect, a topcoat layer can be continuously formed by the same operation.

The 3rd embodiment of the present invention is a manufacturing method of a layered product which combined the 1st mode except the limitation of the thickness of a fluororesin layer, and a desirable mode in the 2nd embodiment.
That is, repeating the operation of electrostatic coating of the powder coating on the base material and baking it twice or more to form a fluororesin layer on the surface of the base material, and form a topcoat layer on the fluororesin layer. A polymer A in a powder coating material for forming a fluororesin layer, wherein the total thickness of the fluororesin layer and the topcoat layer is 50 μm or more. The resin powder containing polymer B and the resin powder containing polymer B in the powder coating material forming the top coat layer each have an average particle diameter of 10 to 500 μm, and the firing temperature when forming the fluororesin layer and the top coat layer is A method for producing the laminate, wherein each is 330 ° C. or more and less than 380 ° C., preferably 350 ° C. or more and less than 380 ° C., and the total time for the firing temperature is 60 minutes or less, respectively. The
In the third embodiment, each of the fluororesin layer and the topcoat layer may have a single layer structure, but the fluororesin layer preferably has a structure of two or more layers, and the topcoat layer has a structure of one or more layers. Preferably it consists of.
The thickness of the fluororesin layer is preferably 30 μm or more, and more preferably 50 μm or more. The thickness of the top coat layer is preferably 20 μm or more, and more preferably 40 μm or more. Further, the total thickness of the fluororesin layer and the top coat layer is preferably 750 μm or less, and more preferably 500 μm or less.

[Laminate]
A fourth embodiment of the present invention is a laminate including a stainless steel base material and a fluororesin layer having a thickness of 50 μm or more formed on the base material surface. The fluororesin layer contains 90% by mass or more of the polymer A ′. The peel strength between the fluororesin layer and the substrate is 14 N / cm or more.
The laminated body of the 4th aspect of this invention can be manufactured with the manufacturing method of the laminated body of the 1st aspect of this invention, for example.

The polymer A ′ is a TFE / PAVE copolymer or a TFE / HFP copolymer and a fluorine-containing copolymer having a functional group (i). As the polymer A ′, the polymer A ¹ and the polymer A ² are preferable, and the polymer A ¹ is particularly preferable.
Content of polymer A 'in a fluororesin layer is 90 mass% or more, 95 mass% or more is preferable, 97 mass% or more is more preferable, 100 mass% or more is especially preferable.

  The peel strength between the fluororesin layer and the substrate is preferably 15 to 100 N / cm, more preferably 16 to 90 N / cm, and particularly preferably 16 to 85 N / cm. When the peel strength between the fluororesin layer and the substrate is not less than the lower limit of the above range, the adhesion between the fluororesin layer and the substrate is excellent, and the fluororesin layer is difficult to peel off.

The 5th aspect of this invention is a laminated body provided with the base material made from stainless steel, and the fluororesin layer and topcoat layer which were formed in the said base-material surface. The fluororesin layer contains 90% by mass or more of the polymer A ′, and the topcoat layer contains a second fluorine-containing copolymer different from the polymer A ′. The total thickness of the fluororesin layer and the topcoat layer is 50 μm or more, and the peel strength between the fluororesin layer and the substrate is 14 N / cm or more.
The second fluorine-containing copolymer is preferably the polymer B, and among them, a TFE / PAVE copolymer and a TFE / HFP copolymer are particularly preferable.
The laminated body of the 5th aspect of this invention can be manufactured with the manufacturing method of the laminated body of the 3rd aspect of this invention, for example.
As in the fourth embodiment, the peel strength between the fluororesin layer and the substrate is preferably 15 to 100 N / cm, more preferably 16 to 90 N / cm, and particularly preferably 16 to 85 N / cm.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by the following description. Examples 1, 2 and 8 are examples, and examples 3 to 7 are comparative examples.
[Measuring method]
Various measurement methods for the fluorinated copolymer and the resin powder are shown below.
(1) Copolymer composition Among the copolymer composition of the fluorinated copolymer, the proportion (mol%) of units based on NAH was determined by the following infrared absorption spectrum analysis. The proportion of other units was determined by melt NMR analysis and fluorine content analysis.

<Ratio of units based on NAH (mol%)>
The fluorine-containing copolymer was press-molded to obtain a film having a thickness of 200 μm, and then analyzed by infrared spectroscopy to obtain an infrared absorption spectrum. In the infrared absorption spectrum, an absorption peak at a unit based on NAH in the fluorine-containing copolymer appears at 1778 cm ⁻¹ . The absorbance of the absorption peak was measured, and the proportion of units based on NAH in the fluorinated copolymer was determined using a molar absorption coefficient of NAH of 20810 mol ⁻¹ · l · cm ⁻¹ .

(2) Melting point (° C)
Using a differential scanning calorimeter (DSC apparatus) manufactured by Seiko Electronics Co., Ltd., record the melting peak when the fluorine-containing copolymer is heated at a rate of 10 ° C./min, and record the temperature (° C.) corresponding to the maximum value. The melting point (Tm) was used.

(3) MFR (g / 10 min)
Using a melt indexer manufactured by Techno Seven, the mass (g) of the fluorine-containing copolymer flowing out for 10 minutes (unit time) from a nozzle with a diameter of 2 mm and a length of 8 mm under a load of 372 ° C. and 49 N was measured. MFR.

(4) Average particle size of fluorine-containing copolymer 2.000 mesh sieve (aperture 2.400 mm), 1.410 mesh sieve (aperture 1.705 mm), 1.000 mesh sieve (aperture 1.205 mm) 0.710 mesh sieve (aperture 0.855 mm), 0.500 mesh sieve (aperture 0.605 mm), 0.250 mesh sieve (aperture 0.375 mm), 0.149 mesh sieve (aperture 0. 100 mm), and a saucer were stacked in this order from the top. A sample (fluorinated copolymer) was added from above and sieved with a shaker for 30 minutes. Thereafter, the mass of the sample remaining on each sieve was measured, and the cumulative total of the passing mass with respect to each opening value was shown in a graph, and the particle size when the total passing mass was 50% was taken as the average particle size of the sample. .

(5) Measurement of average particle size of resin powder Using a laser diffraction / scattering type particle size distribution measuring device (LA-920 measuring device) manufactured by Horiba, Ltd., the resin powder is dispersed in water, and the particle size distribution is measured. The particle size was calculated.

(6) Loosely packed bulk density and densely packed bulk density The loosely packed bulk density and the densely packed bulk density of the resin powder were measured using the methods described in [0117] and [0118] of International Publication No. 2016/017801. .

(7) Peel strength The surface of the laminate of each example was cut at 10 mm intervals using a cutter knife, peeled off part of the fluororesin layer, and then fixed to the chuck of a tensile tester. The peel strength (N / cm) when peeled 90 ° at a pulling speed of 50 mm / min was measured.

(8) Appearance evaluation The surface on the fluororesin layer side of the laminate of each example was visually confirmed and evaluated according to the following evaluation criteria.
Evaluation criteria ○: Foaming and cracks are not observed in the fluororesin layer.
X: Foaming or cracks are observed in the fluororesin layer.

[Production Example 1]
NAH (hydramic anhydride, manufactured by Hitachi Chemical Co., Ltd.) is used as a monomer for forming the unit (1), and PPVE (CF ₂ = CFO (CF ₂ ) ₃ F, manufactured by Asahi Glass Co., Ltd.) is used as the monomer for forming the PAVE unit. It was used to produce polymers ^{a 1} in the procedure described in [0123] of WO 2016/017801.
Copolymerization composition of the polymer ^{A 1} produced was NAH units / TFE units / PPVE units = 0.1 / 97.9 / 2.0 (mol%). The melting point of the produced polymer ^{A 1} is 300 ° C., MFR is 17.6 g / 10 min, the average particle diameter was 1554Myuemu.

Then, using polymer ^{A 1} produced, in WO 2016/017801 [0123] Procedure (manufacturing resin powder, hereinafter referred to. "Powder a") resin powder in according to was obtained. The average particle diameter of the powder a was 22.08 μm, the loosely packed bulk density was 0.513 g / mL, and the densely packed bulk density was 0.686 g / mL.

  As a resin powder made of a fluorine-containing copolymer not containing the unit (1), a resin powder made of PFA having no functional group (i) (trade name “MP-102” manufactured by DuPont) was prepared. Hereinafter, this resin powder is referred to as “powder b”. The average particle diameter of the powder b was 14.03 μm, the loosely packed bulk density was 0.8109 g / mL, and the densely packed bulk density was 1.1351 g / mL.

[Example 1]
The surface of a SUS304 stainless steel plate having a length of 40 mm, a width of 150 mm, and a thickness of 1.2 mm was subjected to sand blasting using 60 mesh alumina particles so that the surface roughness Ra was 5 to 10 μm, and then the surface was cleaned with ethanol. A substrate was prepared.
The operation of electrostatic coating the powder coating material made of powder a obtained in Production Example 1 on the surface of the base material and baking it at a baking temperature of 350 ° C. for a baking time of 4 minutes was repeated 5 times. An operation of electrocoating and firing at a firing temperature of 350 ° C. and a firing time of 6 minutes was performed once to obtain a laminate in which a fluororesin layer having a thickness of 314 μm was formed on the substrate.

[Example 2]
In the same manner as in Example 1 except that the electrostatic coating and firing repeated operation was changed to an operation in which the powder coating was electrostatically coated and fired at a firing temperature of 370 ° C. and a firing time of 3 minutes, repeated 6 times. A laminate in which a fluororesin layer having a thickness of 282 μm was formed on the substrate was obtained.

[Example 3]
In the same manner as in Example 1 except that the electrostatic coating and firing repeated operation was changed to an operation in which the powder coating was electrostatically coated and fired at a firing temperature of 330 ° C. and a firing time of 10 minutes, repeated 6 times. A laminate in which a fluororesin layer having a thickness of 252 μm was formed on the substrate was obtained.

[Example 4]
In the same manner as in Example 1, except that the electrostatic coating and firing repeated operation was changed to an operation in which the powder coating was electrostatically coated and fired at a firing temperature of 340 ° C. and a firing time of 10 minutes was repeated six times. A laminate in which a fluororesin layer having a thickness of 321 μm was formed on the substrate was obtained.

[Example 5]
In the same manner as in Example 1, except that the electrostatic coating and firing repeated operation was changed to an operation in which the powder coating was electrostatically coated and fired at a firing temperature of 380 ° C. and a firing time of 10 minutes, repeated 6 times. A laminate having a fluororesin layer formed on the substrate was obtained. Foaming was observed in the fluororesin layer of the obtained laminate, and the film thickness and peel strength were not measurable.

[Example 6]
Using powder coating consisting of powder b as the powder coating, electrostatic coating and firing repeated operations are repeated six times by electrostatic coating of the powder coating and firing at a firing temperature of 340 ° C. and a firing time of 10 minutes. Except having changed to operation, it carried out similarly to Example 1, and obtained the laminated body in which the fluororesin layer of thickness 177 micrometers was formed on the base material.

[Example 7]
Using powder coating consisting of powder b as the powder coating, electrostatic coating and firing repeated operations are repeated 6 times by electrostatic coating of the powder coating and firing at a firing temperature of 360 ° C. and a firing time of 10 minutes. Except having changed into operation, it carried out similarly to Example 1, and obtained the laminated body in which the fluororesin layer of thickness 139 micrometers was formed on the base material.

The production conditions and evaluation results for each example are shown in Table 1.

As shown in Table 1, in the laminates of Examples 1 and 2 manufactured by the manufacturing method of the present invention, the deterioration of the appearance due to foaming and cracks is suppressed, the peel strength is high, the fluororesin layer and the substrate Excellent adhesion.
On the other hand, the laminates of Examples 3 and 4 having a firing temperature of less than 350 ° C. had lower peel strength than the laminates of Examples 1 and 2, and the adhesion between the fluororesin layer and the substrate was inferior. In Example 5 where the firing temperature was 380 ° C. or higher, foaming was observed in the fluororesin layer, and the appearance was poor. The laminates of Examples 6 and 7 using resin powder made of a fluoropolymer not containing the unit (1) have a lower peel strength than the laminates of Examples 1 and 2, and the adhesion between the fluororesin layer and the substrate The sex was inferior.

[Example 8]
A substrate was prepared in the same manner as in Example 1.
The operation of electrostatic coating the powder coating material made of powder a obtained in Production Example 1 on the surface of the base material and firing it at a firing temperature of 330 ° C. for a firing time of 10 minutes was repeated twice. Further, P-62X (PFA without functional group (i) manufactured by Asahi Glass Co., Ltd., average particle size 233 μm) was electrostatically coated and fired twice at a firing temperature of 330 ° C. and a firing time of 10 minutes. A laminate was obtained in which the total thickness of the fluororesin layer and the topcoat layer was 232 μm.
The peel strength between the fluororesin layer and the substrate of the obtained laminate is 17.1 [N / cm], which is excellent in adhesion, and no foaming and cracks are observed in the fluororesin layer and the topcoat layer. Appearance was also excellent.

The shape and application of the laminate are not particularly limited. Examples of the shape of the laminate include pipes, tubes, films, plates, tanks, rolls, vessels, valves, elbows, and the like.
Applications of laminates include various containers, pipes, tubes, tanks, pipes, fittings, rolls, autoclaves, heat exchangers, distillation towers, jigs, valves, stirring blades, tank trucks, pumps, blower casings, centrifuges Examples include separators and cooking equipment. In addition, since the laminate of the present invention has excellent insulating properties while saving space, it can be suitably used for an insulation amplifier, an insulation transformer, an alternator for an automobile, an electric motor for a hybrid car, and the like.
In addition, the entire content of the specification, claims and abstract of Japanese Patent Application No. 2006-201110 filed on October 12, 2016 is incorporated herein as the disclosure of the specification of the present invention. It is.

Claims (15)

A base material and a fluororesin layer characterized by forming a fluororesin layer having a thickness of 50 μm or more on the surface of the base material by repeating an operation of electrostatic coating and baking the powder coating on the base material twice or more. A method for producing a laminate comprising:
The powder paint includes a resin powder having an average particle size of 10 to 500 μm containing the following polymer A,
The manufacturing method of the said laminated body which sets baking temperature to 350 degreeC or more and less than 380 degreeC, and makes the total time set to the said baking temperature 60 minutes or less.
Polymer A: having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group, including a unit based on tetrafluoroethylene, and having a melting point of 260 to 320 ° C. , Fluorine-containing copolymer.   The manufacturing method of the laminated body of Claim 1 whose said polymer A is a fluorine-containing copolymer containing the unit which has the said functional group.   The polymer A is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having the functional group or a tetrafluoroethylene / hexafluoropropylene copolymer having the functional group. The manufacturing method of the laminated body of description.   The manufacturing method of the laminated body of any one of Claims 1-3 which sets the thickness of the said fluororesin layer to 100 micrometers or more.   The manufacturing method of the laminated body of any one of Claims 1-4 whose said base material is a stainless steel base material.   The topcoat layer which manufactures a laminated body by the method in any one of Claims 1-5, and contains the 2nd fluorine-containing copolymer different from the said polymer A on the surface of the fluororesin layer of the obtained laminated body A process for producing a laminate, characterized in that   The manufacturing method of the laminated body of Claim 6 which forms the said topcoat layer by the powder coating using the resin powder containing a said 2nd fluorine-containing copolymer.   The second fluorine-containing copolymer is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having no functional group or a tetrafluoroethylene / hexafluoropropylene copolymer having no functional group. The manufacturing method of the laminated body of Claim 6 or 7. The operation of electrostatic coating of the powder coating on the base material and baking is repeated twice or more to form a fluororesin layer on the surface of the base material, and a topcoat layer is formed on the fluororesin layer. A method for producing a laminate comprising a base material and a fluororesin layer,
The total thickness of the fluororesin layer and the topcoat layer is 50 μm or more,
The powder coating material forming the fluororesin layer includes a resin powder having an average particle size of 10 to 500 μm and containing the following polymer A:
The powder coating material for forming the topcoat layer includes a resin powder having an average particle size of 10 to 500 μm including a second fluorine-containing copolymer different from the following polymer A,
The manufacturing method of the said laminated body which sets the calcination temperature at the time of forming a fluororesin layer and a topcoat layer to 330 degreeC or more and less than 380 degreeC, respectively, and makes the total time set to the said calcination temperature 60 minutes or less, respectively.
Polymer A: having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group, including a unit based on tetrafluoroethylene, and having a melting point of 260 to 320 ° C. , Fluorine-containing copolymer.   The manufacturing method of the laminated body of Claim 9 whose said polymer A is a fluorine-containing copolymer containing the unit which has the said functional group.   The polymer A is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having the functional group or a tetrafluoroethylene / hexafluoropropylene copolymer having the functional group. The manufacturing method of the laminated body of description.   The second fluorine-containing copolymer is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having no functional group or a tetrafluoroethylene / hexafluoropropylene copolymer having no functional group. The manufacturing method of the laminated body of any one of Claims 9-11. Comprising a stainless steel base material and a fluororesin layer having a thickness of 50 μm or more formed on the surface of the base material;
The fluororesin layer contains 90% by mass or more of the following polymer A ′,
A laminate having a peel strength between the fluororesin layer and the substrate of 14 N / cm or more.
Polymer A ′: a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer or a tetrafluoroethylene / hexafluoropropylene copolymer, and comprising a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group A fluorine-containing copolymer having at least one functional group selected from the group. A base material made of stainless steel, and a fluororesin layer and a topcoat layer formed on the surface of the base material,
The fluororesin layer contains 90% by mass or more of the following polymer A ′,
The topcoat layer includes a second fluorine-containing copolymer different from the following polymer A ′,
The total thickness of the fluororesin layer and the topcoat layer is 50 μm or more,
A laminate having a peel strength between the fluororesin layer and the substrate of 14 N / cm or more.
Polymer A ′: a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer or a tetrafluoroethylene / hexafluoropropylene copolymer, and comprising a carbonyl group-containing group, a hydroxy group, an epoxy group, and an isocyanate group A fluorine-containing copolymer having at least one functional group selected from the group.   The second fluorine-containing copolymer is a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer having no functional group or a tetrafluoroethylene / hexafluoropropylene copolymer having no functional group. The laminate according to claim 14.