KR102391046B1 - Laminate and its manufacturing method - Google Patents

Abstract

A method for producing a laminate that is simple and low-cost and capable of forming a fluororesin layer having excellent adhesion to a substrate and suppressing foaming and cracking, and a laminate comprising a fluororesin layer having excellent adhesion to a substrate provides The operation of electrostatically coating and firing a powder coating material containing a specific fluorinated copolymer and containing a resin powder having an average particle diameter of 10 to 500 µm on a substrate is repeated twice or more, and the firing temperature is 350°C or more and less than 380°C, and the firing total The manufacturing method of the laminated body which sets it as time 60 minutes or less and forms a 50-micrometer-thick fluororesin layer. Further, a method for producing a laminate in which a top coat layer containing a second fluorinated copolymer is formed on the surface of the resin layer. In addition, a stainless steel base material and a fluororesin layer having a thickness of 50 µm or more on the surface of the base material are provided, wherein the resin layer contains 90 mass% or more of a specific fluorinated copolymer, and the peel strength between the resin layer and the base material is 14 N /cm or more, the laminate. and the top coat layer on a surface of the resin layer.

Description

Laminate and its manufacturing method

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

Fluorinated polymers such as tetrafluoroethylene/perfluoro(alkylvinyl ether) copolymer (PFA) have a low coefficient of friction and are excellent in properties such as non-tackiness, chemical resistance and heat resistance. It is widely used for surface processing of kitchen utensils such as frying pans and pots, household items such as irons, electrical industrial goods, and mechanical industrial goods. For example, a method is known in which a powder coating material containing a fluorinated polymer is coated on the surface of a base material such as a frying pan and fired to form a fluororesin layer to obtain a laminate.

However, the fluorinated polymer is particularly poor in adhesion to a stainless steel substrate. Then, for the purpose of improving adhesiveness, forming a primer layer between a base material and a fluororesin layer is proposed. For example, a primer in which a binder resin such as a heat-resistant resin and a fluorinated polymer are blended is previously applied as a primer on a substrate to form a primer layer, and on the primer layer, a powder coating containing a fluorinated polymer is applied. The method of forming a fluororesin layer by this is mentioned (patent document 1). However, the method of forming the primer layer is disadvantageous in terms of cost as well as complicated manufacturing method.

By the way, as a resin powder excellent in adhesiveness to a base material, the resin powder which consists of a fluorine-containing polymer which has specific functional groups, such as a carbonyl group containing group, is known (patent document 2).

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

However, as a result of investigation by the present inventors, when the resin powder of Patent Document 2 is electrostatically coated on a base material as a powder coating material and firing is repeated twice or more to form a fluororesin layer having a thickness of 50 µm or more, the fluororesin layer is It turned out that foaming and a crack are easy to produce.

The present invention provides a method for manufacturing a laminate that is easy to manufacture, is low cost, and can form a fluororesin layer having excellent adhesion to a substrate and suppressing foaming and cracking, and a fluororesin layer having excellent adhesion to a substrate. A laminate is provided.

This invention has the following structures.

[1] A laminate comprising a base material and a fluororesin layer, wherein a fluororesin layer having a thickness of 50 µm or more is formed on the surface of the base material by repeating the operation of electrostatically coating the powder coating material on the base material and firing it twice or more As a manufacturing method of

The powder coating material contains a resin powder having an average particle diameter of 10 to 500 µm containing the following polymer A,

The manufacturing method of the said laminated body which sets a calcination temperature to 350 degreeC or more and less than 380 degreeC, and sets the total time to set to the said calcination temperature into 60 minutes or less.

Polymer A: a fluorine-containing group having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group and an isocyanate group, and containing a unit based on tetrafluoroethylene, melting point of 260 to 320°C copolymer.

[2] The method for producing a laminate according to [1], wherein the polymer A is a fluorinated copolymer containing a unit having the functional group.

[3] The polymer A is a tetrafluoroethylene/perfluoro(alkylvinyl ether) copolymer having the functional group, or a tetrafluoroethylene/hexafluoropropylene copolymer having the functional group, [1] or [ 2] of the manufacturing method of the laminated body.

[4] The method for producing a laminate according to any one of [1] to [3], wherein the fluororesin layer has a thickness of 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 tower containing a second fluorinated copolymer different from the polymer A on the surface of the fluororesin layer of the laminate obtained by producing a laminate by the method of any one of [1] to [5] above A method for producing a laminate, comprising forming a coating layer.

[7] The method for producing a laminate according to [6], wherein the top coat layer is formed by powder coating using a resin powder containing the second fluorinated copolymer.

[8] The second fluorinated copolymer is a tetrafluoroethylene/perfluoro(alkylvinyl ether) copolymer having no functional group or a tetrafluoroethylene/hexafluoropropylene copolymer having no functional group. , [6] or [7], the manufacturing method of the laminate.

[9] A base material and fluorine, characterized in that a fluorine resin layer is formed on the surface of the base material by repeating an operation of electrostatically coating a powder coating material on a base material and firing it twice or more, and a top coat layer is formed on the fluororesin layer As a manufacturing method of a laminated body provided with a resin layer,

The total thickness of the fluororesin layer and the top coat layer is 50 μm or more,

The powder coating material for forming the fluororesin layer contains a resin powder having an average particle diameter of 10 to 500 µm containing the following polymer A,

The powder coating material for forming the top coat layer contains a resin powder having an average particle diameter of 10 to 500 µm and containing a second fluorinated copolymer different from the following polymer A;

A method for producing the laminate, wherein the firing temperatures for forming the fluororesin layer and the top coat layer are respectively 330°C or higher and less than 380°C, and the total time at the firing temperature is 60 minutes or less, respectively.

Polymer A: a fluorine-containing group having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group and an isocyanate group, and containing a unit based on tetrafluoroethylene, melting point of 260 to 320°C copolymer.

[10] The method for producing a laminate according to [9], wherein the polymer A is a fluorinated copolymer containing a unit having the functional group.

[11] wherein the polymer A is a tetrafluoroethylene/perfluoro(alkylvinyl ether) copolymer having the functional group, or a tetrafluoroethylene/hexafluoropropylene copolymer having the functional group, [9] or [ 10] of the manufacturing method of the laminate.

[12] The second fluorinated copolymer is a tetrafluoroethylene/perfluoro(alkylvinyl ether) copolymer having no functional group or a tetrafluoroethylene/hexafluoropropylene copolymer having no functional group. , The method for producing a laminate according to any one of [9] to [11].

[13] A base material made of stainless steel, and a fluororesin layer having a thickness of 50 µm or more formed on the surface of the base material;

The said fluororesin layer contains 90 mass % or more of the following polymer A',

A laminate, characterized in that the peel strength between the fluororesin layer and the substrate is 14 N/cm or more.

Polymer A': tetrafluoroethylene/perfluoro(alkylvinylether) copolymer, or tetrafluoroethylene/hexafluoropropylene copolymer, and from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group and an isocyanate group A fluorinated copolymer having at least one selected functional group.

[14] A base material made of stainless steel, and a fluororesin layer and a top coat layer formed on a surface of the base material;

The said fluororesin layer contains 90 mass % or more of the following polymer A',

The top coat layer contains a second fluorinated copolymer different from the following polymer A';

The total thickness of the fluororesin layer and the top coat layer is 50 μm or more,

A laminate, characterized in that the peel strength between the fluororesin layer and the substrate is 14 N/cm or more.

Polymer A': tetrafluoroethylene/perfluoro(alkylvinylether) copolymer, or tetrafluoroethylene/hexafluoropropylene copolymer, and from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group and an isocyanate group A fluorinated copolymer having at least one selected functional group.

[15] The second fluorinated copolymer is a tetrafluoroethylene/perfluoro(alkylvinyl ether) copolymer having no functional group or a tetrafluoroethylene/hexafluoropropylene copolymer having no functional group. , the laminate of [14].

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

The laminate of this invention is equipped with the fluororesin layer excellent in adhesiveness with a base material.

The meaning of the following terms in this specification is as follows.

"Average particle diameter of resin powder" is a volume-based cumulative 50% diameter (D50) calculated|required by laser diffraction/scattering method. That is, the particle size distribution is measured by the laser diffraction/scattering method, a cumulative curve is obtained by taking the total volume of the particle population as 100%, and it is the particle diameter at the point where the cumulative volume becomes 50% on the cumulative curve.

The "melt flow rate" is a melt mass flow rate (MFR) specified in JIS K 7210: 1999 (ISO 1133: 1997).

The "unit" in the polymer means an atomic group derived from one molecule of the monomer formed by polymerization of the monomer. The unit may be an atomic group directly formed by the polymerization reaction, or an atomic group in which a part of the atomic group is converted into another structure by treating the polymer obtained by the polymerization reaction.

"(meth)acrylate" is a generic term for an acrylate and a methacrylate.

[Method for producing a laminate]

A first aspect of the present invention is a laminate comprising a base material and a fluororesin layer by repeating an operation of electrostatically coating and firing a powder coating material on a base material twice or more to form a fluororesin layer having a thickness of 50 µm or more on the surface of the base material It is a manufacturing method of a laminated body which obtains a sieve.

When the operation of electrostatic coating and firing is repeated two or more times, the powder coating material in each operation may be the same or may be different powder coating materials within the scope of the first aspect of the present invention. For example, although both are polymer ^A , you may manufacture a laminated body using ² types of powder coating materials containing different polymers (for example, the polymer A1 and polymer A2 mentioned later).

A well-known method can be employ|adopted for the method of electrostatically coating a powder coating material.

A well-known method can be employ|adopted as a baking method.

Firing temperature shall be 350 degreeC or more and less than 380 degreeC. When the firing temperature is 350°C or higher, the formed fluororesin layer and the substrate have excellent adhesion. When the calcination temperature is less than 380°C, it is possible to suppress the occurrence of foaming and cracks in the fluororesin layer, and a laminate having an excellent external appearance is obtained. 350-375 degreeC is preferable and, as for a calcination temperature, 350-370 degreeC is more preferable.

The firing temperature of each firing in two or more firings may be different or may be the same temperature.

When calcining is performed two or more times, the total time set at the calcination temperature (hereinafter, also referred to as "total time of calcination") is 60 minutes or less, preferably 3 to 60 minutes, more preferably 4 to 60 minutes, , more preferably 5 to 45 minutes, particularly preferably 10 to 30 minutes. When the total time of firing is equal to or less than the upper limit of the above range, it is possible to suppress the occurrence of foaming and cracks in the fluororesin layer, and a laminate having an excellent external appearance is obtained. It is excellent in the adhesiveness of the fluororesin layer and a base material to be formed that the total time of baking is more than the lower limit of the said range.

1 to 20 minutes are preferable and, as for the baking time of each baking, 1 to 15 minutes are more preferable. When the calcination time of each calcination is equal to or more than the lower limit of the above range, the resin is sufficiently melted and the surface smoothness is excellent. When the firing time of each firing is equal to or less than the upper limit of the above range, foaming and cracking tend to be suppressed.

The firing time of each firing in two or more firings may be different and may be the same.

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

The lower limit of the thickness of the fluororesin layer to form is 50 micrometers, and 100 micrometers is preferable from the point of process shortening. 750 micrometers is preferable from the point of chemical-resistance improvement, and, as for the upper limit of the thickness of a fluororesin layer, 500 micrometers is more preferable.

A powder coating material contains the resin powder with an average particle diameter of 10-500 micrometers containing the polymer A.

Polymer A has at least one functional group (hereinafter also referred to as “functional group (i)”) selected from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group and an isocyanate group, and a unit based on tetrafluoroethylene It contains a fluorine-containing copolymer having a melting point of 260 to 320°C.

Hereinafter, tetrafluoroethylene is referred to as "TFE", and "a unit based on TFE" is also referred to as a "TFE unit".

Rather than being a polymer having a melting point, polymer A is not a homopolymer of TFE, but a copolymer containing units based on monomers other than TFE. The unit based on monomers other than TFE contained in the polymer A is not limited to one, and two or more may be used. Examples of the unit based on a monomer other than TFE include a unit based on a fluorine-containing monomer other than TFE and a unit based on a monomer having no fluorine atom. Moreover, the functional group (i) may exist in the unit contained in the polymer A, and may exist in the terminal group which exists in the terminal of the main chain of the polymer A.

It is preferable that the functional group (i) exists in the 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 not having a fluorine atom, but is preferably a unit based on a monomer having no fluorine atom. .

When the functional group (i) exists in a terminal group present at the terminal of the main chain of the polymer A, the terminal group having the functional group (i) is derived from a polymerization initiator, a chain transfer agent, etc. used in the production of the polymer A is a terminal group that The polymer A may contain both the unit which has a functional group (i), and the terminal group which has a functional group (i).

In addition, hereafter, "the unit which has a functional group (i)" is also called "unit (1)".

The polymer A preferably contains, as a unit other than the TFE unit, a unit based on a fluorinated monomer other than TFE (excluding the unit (1)). 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, hereafter, "hexafluoropropylene" is also called "HFP", and "unit based on HFP" is also called "HFP unit". Hereinafter, the PAVE unit and the HFP unit are collectively referred to as "unit (3)".

Polymer A contains the TFE unit and the unit (3), and by appropriately adjusting the content ratio of both, it is easy to form a fluorinated polymer having the above melting point. As will be described later, the physical properties of the polymer A, such as the melting point and melt flow rate (MFR), rarely depend on the presence or absence of the unit (1) or the presence or absence of the functional group (i) of the terminal group, mainly the TFE unit and the unit It is adjusted by the relative ratio or molecular weight of (3). The polymer A containing the unit (3) may contain both a PAVE unit and an HFP unit as the unit (3).

The polymer A may contain units other than the unit (3) (however, the unit (1) is excluded) as units other than the TFE unit. Units other than the unit (1), the TFE unit, and the unit (3) are also referred to as “unit (4)” hereinafter. Examples of the monomer forming the unit (4) include fluorinated monomers other than PAVE and HFP, and monomers having no fluorine atom. Polymer A may be a copolymer containing at least 1 type of unit (4) and a TFE unit.

Examples of the copolymer containing at least one type of unit (4) and a TFE unit include a copolymer containing a TFE unit, unit (3) and unit (4), and unit (1) and a TFE unit and unit (3) Copolymers containing the unit (4) are preferred.

The functional group (i) is a functional group selected from the group consisting of a carbonyl group-containing group, a hydroxyl 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 its structure. For example, a group having a carbonyl group between carbon atoms of the hydrocarbon group, a carbonate group, a carboxy group, a haloformyl group, an alkoxycarbonyl group, an acid anhydride residue, poly A fluoroalkoxy carbonyl group, a fatty acid residue, etc. are mentioned. Among them, a group selected from the group consisting of 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 in view of improving adhesion to the substrate is preferable, and a carboxy group and An acid anhydride residue is more preferable.

As a hydrocarbon group in the group which has a carbonyl group between carbon atoms of a hydrocarbon group, a C2-C8 alkylene group etc. are mentioned, for example. In addition, the number of carbon atoms in the alkylene group is the number of carbon atoms in parts other than the carbonyl group in the alkylene group. The alkylene group may be linear or branched.

The haloformyl group is a group represented by -C(=O)-X (provided that X is a halogen atom). A fluorine atom, a chlorine atom, etc. are mentioned as a halogen atom in a haloformyl group, A fluorine atom is preferable. That is, as the haloformyl group, a fluoroformyl group (also referred to as a carbonyl fluoride group) is preferable.

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.

As the unit (1), a unit based on a monomer having a functional group (i) (hereinafter also referred to as “monomer (m1)”) is preferable. The number of functional groups (i) which a monomer (m1) has may be one, or two or more may be sufficient as it. When the monomer (m1) has two or more functional groups (i), these functional groups (i) may be the same or different, respectively.

As a monomer (m1), the compound which has one functional group (i) and has one polymerizable double bond is preferable.

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 also referred to as “monomer (m11)”), a monomer having a carboxyl group ( Hereinafter also referred to as "monomer (m12)"), vinyl ester, (meth)acrylate, CF ₂ =CFOR ^f1 COOX ¹ (provided that R ^f1 is a purple having 1 to 10 carbon atoms which may have an ethereal oxygen atom) It is a luoroalkylene group, and X< ¹ > is a hydrogen atom or a C1-C3 alkyl group) etc. are mentioned.

As a monomer (m11), the acid anhydride of unsaturated dicarboxylic acid etc. are mentioned, for example. Examples of the acid anhydride of the unsaturated dicarboxylic acid include itaconic acid anhydride (hereinafter also referred to as "IAH"), citraconic acid anhydride (hereinafter also referred to as "CAH"), 5-norbornene-2; 3-dicarboxylic acid anhydride (an alias: hymic anhydride. Hereinafter, it is also called "NAH"), maleic anhydride, etc. are mentioned.

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, etc. are mentioned.

Examples of the vinyl ester include vinyl acetate, vinyl chloroacetate, vinyl butanate, vinyl pivalate, vinyl benzoate, and vinyl crotonate.

As (meth)acrylate, (polyfluoroalkyl)acrylate, (polyfluoroalkyl)methacrylate, etc. are mentioned, for example.

As a monomer having a hydroxyl group, for example, vinyl esters, vinyl ethers, allyl ethers, (meth)acrylate-based compounds, etc., compounds having one or more hydroxyl groups in the terminal or side chain, crotonic acid hydride Crotonic acid-modified compounds, such as oxyethyl, allyl alcohol, etc. are mentioned.

As a monomer which has an epoxy group, For example, unsaturated glycidyl ethers (For example, allyl glycidyl ether, 2-methylallyl glycidyl ether, vinyl glycidyl ether, etc.), unsaturated glycidyl ester (For example, glycidyl acrylate, glycidyl methacrylate, etc.) etc. are mentioned.

As a monomer which has an isocyanate group, For example, 2-(meth)acryloyloxyethyl isocyanate, 2-(2-(meth)acryloyloxyethoxy)ethyl isocyanate, 1, 1-bis((meth)) Acryloyloxymethyl)ethyl isocyanate etc. are mentioned.

A monomer (m1) may be used individually by 1 type, and may use 2 or more types together.

It is preferable that the unit (1) 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 them, a monomer selected from the group consisting of IAH, CAH, and NAH is particularly preferable. When at least one member selected from the group consisting of IAH, CAH, and NAH is used, acid anhydride residues are used without using a special polymerization method (refer to Japanese Unexamined Patent Publication No. 11-193312) required when maleic anhydride is used. It is possible to easily prepare a fluorinated copolymer having Among IAH, CAH, and NAH, NAH is preferable from the viewpoint of more excellent adhesion to the substrate.

The unit (3) is a PAVE unit or an HFP unit.

Examples of PAVE include CF ₂ =CFOR ^f2 (provided that R ^f2 is a C1-C10 perfluoroalkyl group which may have an etheric oxygen atom). The perfluoroalkyl group for R ^f2 may be linear or branched. As for the number of carbon atoms of R ^f2 , 1-3 are preferable.

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.

Examples of the monomer forming the unit (4) include the fluorine-containing monomer (hereinafter also referred to as "monomer (m41)") and the monomer having no fluorine atom (hereinafter also referred to as "monomer (m42)"). there is.

The monomer (m41) is preferably a fluorine-containing compound having one polymerizable double bond, for example, vinyl fluoride, vinylidene fluoride (hereinafter also referred to as “VdF”), trifluoroethylene, chlorotrifluoro Fluoroolefins such as ethylene (hereinafter also referred to as “CTFE”) (however, excluding TFE and HFP), CF ₂ =CFOR ^f3 SO ₂ X ³ (provided that R ^f3 is a purple having 1 to 10 carbon atoms) a luoroalkylene group or a perfluoroalkylene group having 2 to 10 carbon atoms having an ethereal oxygen atom, and X ³ is a halogen atom or a hydroxy group), CF ₂ =CF(CF ₂ ) _p OCF=CF ₂ (provided that p is 1 or 2), CH ₂ =CX ⁴ (CF ₂ ) _q X ⁵ (provided that X ⁴ is a hydrogen atom or a fluorine atom, q is an integer of 2 to 10, and X ⁵ is hydrogen atom or fluorine atom) and perfluoro (2-methylene-4-methyl-1,3-dioxolane). These may be used individually by 1 type, and may be used 2 or more types.

The monomer (m41) is preferably a monomer selected from the group consisting of VdF, CTFE, and CH ₂ =CX ⁴ (CF ₂ ) _q X ⁵ .

CH ₂ =CX ⁴ (CF ₂ ) _q X ⁵ , then 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, with CH ₂ =CH(CF ₂ ) ₄ F and CH ₂ =CH(CF ₂ ) ₂ F being preferred.

As a monomer (m42), the compound which does not have a fluorine atom which has one polymerizable double bond is preferable, For example, C3 or less olefins, such as ethylene and propylene, etc. are mentioned. These may be used individually by 1 type, and may be used 2 or more types.

As the monomer (m42), ethylene and propylene are preferable, and ethylene is particularly preferable.

The monomer which forms the 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 1 or more types of monomers (m42) may be used together. do.

Examples of the polymer A include a fluorinated copolymer containing the unit (1) and a TFE unit and a PAVE unit (hereinafter also referred to as “polymer A ¹ ”), and a fluorinated copolymer containing the unit (1), a TFE unit and an HFP unit. Coalescing (hereinafter also referred to as “polymer A ² ”) is preferable, and polymer A ¹ is particularly preferable. Hereinafter, these fluorinated copolymers will be described in detail.

The polymer A ¹ contains a unit (1), a TFE unit, and a PAVE unit, the proportion of the unit (1) with respect to the total of all units is 0.01 to 3 mol%, and the proportion of the TFE unit is 90 to 99.89 mol %, preferably a fluorinated copolymer having a PAVE unit ratio of 0.1 to 9.99 mol%.

Polymer A ¹ may further contain at least one of an HFP unit and unit (4) as needed. Polymer A ¹ may consist of unit (1), a TFE unit, and a PAVE unit, may consist of a unit (1), a TFE unit, a PAVE unit, and an HFP unit, and may consist of a unit (1), a TFE unit and a PAVE unit. and unit (4), or unit (1), TFE unit, PAVE unit, HFP unit, and unit (4).

The polymer A ¹ is preferably a copolymer containing a unit based on a monomer having a carbonyl group-containing group, a TFE unit, and a PAVE unit, and a unit based on the monomer (m11), a TFE unit, and a PAVE unit. Copolymers are particularly preferred. Specific examples of the preferred polymer A ¹ include a NAH/TFE/PPVE copolymer, an IAH/TFE/PPVE copolymer, and a CAH/TFE/PPVE copolymer.

Polymer A ¹ may have a functional group (i) as a main chain terminal group. As the functional group (i) as the main chain terminal group, an alkoxycarbonyl group, a carbonate group, a carboxy group, a fluoroformyl group, an acid anhydride residue, and a hydroxy group are preferable. These functional groups can be introduce|transduced by selecting suitably the radical polymerization initiator, a chain transfer agent, etc. used at the time ^of manufacture of polymer A1.

About the ratio of the said unit (1), if it is more than the lower limit of the said range, it is easy to obtain a resin powder with a large bulk density, and it is excellent in the adhesiveness of a fluororesin layer and a base material (metal etc.). When the ratio of the unit (1) is equal to or less than the upper limit of the above range, the heat resistance, color tone, and the like of the polymer A ¹ are good.

As for the ratio of the unit (1), 0.03-2 mol% is more preferable, and its 0.05-1 mol% is especially preferable.

About the ratio of the said TFE unit, polymer A ¹ is excellent in heat resistance, chemical-resistance, etc. as it is more than the lower limit of the said range. When the proportion of TFE units is equal to or less than the upper limit of the above range, the polymer A ¹ is excellent in stress crack resistance.

95-99.47 mol% is more preferable, and, as for the ratio of a TFE unit, 96-98.95 mol% is especially preferable.

About the ratio of the said PAVE unit, if it is in the range ^of the said range, polymer A1 is excellent in moldability.

As for the ratio of the said PAVE unit, 0.5-9.97 mol% is more preferable, and its 1-9.95 mol% is especially preferable.

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

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 proportion (mol%) of the unit (1) in the total units constituting the polymer A ¹ can be obtained using methods such as infrared absorption spectrum analysis. there is.

Polymer A2 contains a unit ( ¹ ), a TFE unit, and an HFP unit, the ratio of the unit (1) with respect to the sum total of all units is 0.01-3 mol%, The ratio of the TFE unit is 90-99.89 mol %, and the copolymer (however, polymer ^A1 is excluded) whose ratio of the HFP unit is 0.1-9.99 mol% is preferable.

Polymer A2 may further contain at least one of a PAVE unit and unit ( ⁴ ) as needed. Polymer A ² may consist of unit (1), a TFE unit, and an HFP unit, or may consist of a unit (1), a TFE unit, an HFP unit, and a PAVE unit (however, polymer A ¹ is excluded), It may consist of unit (1), TFE unit, HFP unit, and unit (4), and it may consist of unit (1), TFE unit, HFP unit, PAVE unit and unit (4) (except for polymer A ¹ ) do) may be

The polymer A ² is preferably a copolymer containing a unit based on a monomer having a carbonyl group-containing group, a TFE unit, and an HFP unit, and a unit based on the monomer (m11), a TFE unit, and an HFP unit. Copolymers are particularly preferred. ^As a specific example of a preferable polymer A2, a NAH/TFE/HFP copolymer, an IAH/TFE/HFP copolymer, a CAH/TFE/HFP copolymer, etc. are mentioned.

Polymer A2 may have ^a functional group (i) as a principal chain terminal group. As a functional group (i) preferable as ^a principal chain terminal group, the thing similar to what was mentioned for polymer A1 is mentioned.

About the ratio of the said unit (1), if it is more than the lower limit of the said range, a resin powder with a large bulk density is easy to be obtained, and it is excellent in the adhesiveness of a fluororesin layer and a base material (metal etc.). ^The heat resistance, color tone, etc. of polymer A2 are favorable that the ratio of unit (1) is below the upper limit of the said range.

As for the ratio of the unit (1), 0.02-2 mol% is more preferable, and its 0.05-1.5 mol% is especially preferable.

About the ratio of the said TFE unit, if it is more than the lower limit of the said range, Polymer A2 is excellent in heat resistance, chemical ^- resistance, etc. When the proportion of TFE units is equal to or less than the upper limit of the above range, the polymer A ² is excellent in stress crack resistance.

91-98 mol% is preferable and, as for the ratio of a TFE unit, 92-96 mol% is especially preferable.

About the ratio of the said HFP unit, it is excellent in peeling strength in it being in the range of the said range.

1-9 mol% is more preferable, and, as for the ratio of an HFP unit, 2-8 mol% is especially preferable.

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

Melting|fusing point of polymer A is 260-320 degreeC, 280-320 degreeC is preferable, 295-315 degreeC is more preferable, 295-310 degreeC is still more preferable. It is excellent in heat resistance as melting|fusing point of polymer A is more than the lower limit of the said range. It is excellent in the balance of heat resistance and workability that melting|fusing point of polymer A is below the upper limit of the said range.

In addition, melting|fusing point of polymer A can be adjusted with the kind, content rate, molecular weight, etc. of the unit which comprises the said polymer A. For example, the higher the proportion of TFE units, the higher the melting point tends to be.

The melt flow rate (MFR) of polymer A is preferably 0.1 to 1000 g/10 min, more preferably 0.5 to 100 g/10 min, still more preferably 1 to 30 g/10 min, still more preferably 5 to 20 g/10 min. Especially preferred. When MFR is at least the lower limit of the above range, a layer having excellent workability and excellent planar smoothness can be formed. When MFR is below the upper limit of the said range, the polymer A is excellent in mechanical strength, and the fluororesin layer is excellent in mechanical strength.

MFR is a reference|standard of the molecular weight of polymer A, when MFR is large, molecular weight is small, and when MFR is small, it shows that molecular weight is large. The molecular weight of the polymer A, furthermore, MFR can be adjusted according to the manufacturing conditions of the polymer A. For example, if the polymerization time is shortened during polymerization of the monomer, the MFR tends to increase.

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

The resin powder may contain fluorinated polymers other than the polymer A, aromatic polyester, polyamideimide, thermoplastic polyimide, and the like as long as it does not impair the effects of the present invention.

80 mass % or more is preferable, as for the ratio of the polymer A with respect to the whole amount of resin powder, 85 mass % or more is more preferable, 90 mass % or more is still more preferable, and its 100 mass % is especially preferable.

The average particle diameter of resin powder is 10-500 micrometers, 15-400 micrometers is preferable, and its 20-300 micrometers is more preferable. When the average particle diameter of the resin powder is equal to or greater than the lower limit of the above range, it is difficult to mix air during electrostatic coating. The fluororesin layer can be made thin as the average particle diameter of a resin powder is below the upper limit of the said range.

A powder coating material may contain components other than resin powder as needed. As other components, a pigment, carbon fiber, graphite, etc. are mentioned.

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 content of resin powder is 100 mass %.

It does not specifically limit as a base material, For example, household articles, such as a frying pan, a pot, and an iron, piping of a factory, etc. are mentioned.

It does not specifically limit as a material of a base material, Metals, such as stainless steel and iron, resin, glass, ceramics, etc. are mentioned. The manufacturing method of the laminated body of this invention is effective especially in the case of the stainless steel base material 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. Copper, iron, aluminum, stainless steel, etc. are mentioned as a metal in metal foil, Especially copper is preferable.

Moreover, a fluororesin layer can be formed by the manufacturing method of this invention also about a bendable metal base material thicker than metal foil and about 0.3-0.5 mm in thickness.

According to the manufacturing method of the laminated body of the 1st aspect of this invention demonstrated above, using the powder coating material containing polymer A and containing the resin powder of a specific average particle diameter, the firing temperature and total time of two or more firings are specified in a specific range. By controlling to , it is possible to manufacture a laminate having a fluororesin layer having excellent adhesion to the substrate and suppressed foaming and cracking. Moreover, since the manufacturing method of the laminated body of this invention does not form a primer layer, manufacture is simple and low cost.

In the second aspect of the present invention, a top coat layer containing a second fluorinated copolymer different from the polymer A is formed on the surface of the fluororesin layer of the laminate produced by the manufacturing method of the first aspect of the present invention. It is a manufacturing method of a laminate, characterized in that.

The second fluorinated copolymer is preferably a fluorinated copolymer of the same category as that of the polymer A (hereinafter, also referred to as "polymer B") except that it does not have the functional group (i). As polymer B, a copolymer containing a TFE unit and a PAVE unit and a copolymer containing a TFE unit and an HFP unit are preferable, and a copolymer containing a TFE unit and a PAVE unit is particularly preferable. It is preferable that the content rate of each unit in such a copolymer is the content rate of each unit at the time of making the content rate of unit (1) 0 in the said polymer A.

The second fluorinated copolymer is not limited to the above polymer B, and various types of thermally meltable fluorinated copolymers can be used.

Although the thickness of a top coat layer is not specifically limited, 10 micrometers or more are preferable, and 30 micrometers or more are preferable. Moreover, it is preferable that it is 750 micrometers or less, and, as for the total thickness of a fluororesin layer and a top coat layer, it is more preferable that it is 500 micrometers or less.

By forming the top coat layer, non-adhesiveness on the surface of the resin layer is improved, and chemical properties such as chemical resistance are further improved.

The top coat layer is preferably formed by a coating method using a powder coating material containing the polymer B, and particularly preferably formed by a method of repeating the operation of electrostatic coating and firing at least once. It is preferable that the powder coating material containing the polymer B or operation of electrostatic coating and baking is the same as that of the first aspect of the present invention. For example, the powder coating material contains a resin powder having an average particle diameter of 10 to 500 µm containing the polymer B, and the firing temperature is 330°C or more and less than 380°C, preferably 350°C or more and less than 380°C, the firing temperature It is preferable to set the total time to be set to 60 minutes or less. In this way, after the fluororesin layer is formed according to the first aspect, the top coat layer can be formed continuously by the same operation.

A third embodiment of the present invention is a method for producing a laminate in which the first aspect excluding the limitation of the thickness of the fluororesin layer and the preferred aspect in the second embodiment are combined.

That is, an operation of electrostatically coating a powder coating material on a substrate and firing is repeated twice or more to form a fluororesin layer on the surface of the substrate, and a top coat layer is formed on the fluororesin layer. A method for producing a laminate including a backing layer, wherein the total thickness of the fluororesin layer and the top coat layer is 50 µm or more, and a resin powder containing polymer A in a powder coating material for forming the fluororesin layer and a top coat layer The resin powder containing the polymer B in the powder coating material forming Preferably, it is 350 degreeC or more and less than 380 degreeC, and it is the manufacturing method of the said laminated body which sets the total time to set to the said calcination temperature into 60 minutes or less, respectively.

In the third embodiment, the fluororesin layer and the topcoat layer may each have a single-layer structure, but the fluororesin layer preferably has a structure of two or more layers, and the topcoat layer preferably has a structure of one or more layers.

30 micrometers or more are preferable and, as for the thickness of the said fluororesin layer, 50 micrometers or more are more preferable. 20 micrometers or more are preferable and, as for the thickness of the said top coat layer, 40 micrometers or more are more preferable. Moreover, 750 micrometers or less are preferable and, as for the sum total of the thickness of a fluororesin layer and a top coat layer, 500 micrometers or less are more preferable.

[Laminate]

A fourth embodiment of the present invention is a laminate comprising a stainless steel substrate and a fluororesin layer having a thickness of 50 µm or more formed on the surface of the substrate. The fluororesin layer contains 90 mass % or more of polymer A'. The peeling strength of the fluororesin layer and the base material is 14 N/cm or more.

The laminate 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.

Polymer A' is a TFE/PAVE copolymer or a TFE/HFP copolymer, and is a fluorinated copolymer having a functional group (i). As polymer ^A ', the said polymer A1 and polymer ^A2 are preferable, and polymer ^A1 is especially 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.

15-100 N/cm is preferable, as for the peeling strength of a fluororesin layer and a base material, 16-90 N/cm is more preferable, 16-85 N/cm is especially preferable. When the peeling strength of the fluororesin layer and the substrate is equal to or greater than the lower limit of the above range, the adhesion between the fluororesin layer and the substrate is excellent, and the fluororesin layer is not easily peeled off.

A fifth aspect of the present invention is a laminate comprising a stainless steel substrate, and a fluororesin layer and a top coat layer formed on the surface of the substrate. The fluororesin layer contains 90 mass % or more of the polymer A', and the top coat layer contains a second fluorinated copolymer different from the polymer A'. The total thickness of the fluororesin layer and the top coat layer is 50 µm or more, and the peel strength between the fluororesin layer and the base material is 14 N/cm or more.

It is preferable that the said 2nd fluorine-containing copolymer is the said polymer B, and among these, a TFE/PAVE copolymer and a TFE/HFP copolymer are especially preferable.

The laminate 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 for the peeling strength of a fluororesin layer and a base material, 15-100 N/cm is preferable similarly to the case of the 4th embodiment, 16-90 N/cm is more preferable, 16-85 N/cm is especially preferable. Do.

Example

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.

[How to measure]

Various measurement methods for the fluorinated copolymer and resin powder are shown below.

(1) copolymer composition

The proportion (mol%) of units based on NAH in the copolymer composition of the fluorinated copolymer was determined by the following infrared absorption spectrum analysis. The ratio of other units was calculated|required by melt|dissolution NMR analysis and fluorine content analysis.

<Ratio of units based on NAH (mol%)>

The fluorinated 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, the absorption peak in the unit based on NAH in the fluorinated copolymer appears at 1778 cm ^-1 . The absorbance of the absorption peak was measured, and the ratio of units based on NAH in the fluorinated copolymer was determined using the molar extinction coefficient 20810 mol ^-1 ·l·cm ^-1 of NAH.

(2) Melting point (℃)

Using a differential scanning calorimeter (DSC device) manufactured by Seiko Electronics Co., Ltd., the melting peak when the temperature of the fluorinated copolymer was raised at a rate of 10° C./min was recorded, and the temperature (° C.) corresponding to the local maximum was determined as the melting point (Tm) ) was set.

(3) MFR (g/10 min)

Using a melt indexer manufactured by Decno Seven, the mass (g) of the fluorinated copolymer flowing out from a nozzle having a diameter of 2 mm and a length of 8 mm for 10 minutes (unit time) under a load of 372° C. and 49 N was measured It was measured and it was set as MFR.

(4) Average particle size of fluorinated copolymer

2.000 mesh sieve (mesh 2.400 mm), 1.410 mesh sieve (mesh 1.705 mm), 1.000 mesh sieve (mesh 1.205 mm), 0.710 mesh sieve (mesh 0.855 mm), 0.500 mesh sieve (mesh 0.605 mm), 0.250 mesh sieve (mesh) 0.375 mm), 0.149 mesh sieve (mesh 0.100 mm), and a saucer were stacked in this order from above. A sample (fluorinated copolymer) was placed thereon, and sieving was performed on a shaker for 30 minutes. Thereafter, the mass of the sample remaining on each sieve was measured, the cumulative passing mass for each mesh value was plotted on the graph, and the particle size when the cumulative passing mass was 50% was taken as the average particle diameter of the sample.

(5) Measurement of average particle size of resin powder

The resin powder was dispersed in water using a laser diffraction/scattering particle size distribution analyzer (LA-920 measuring instrument) manufactured by Horiba Corporation, and the particle size distribution was measured to calculate the average particle size.

(6) Small packing bulk density and wheat packing bulk density

The small packing bulk density and tight packing bulk density of the resin powder were measured using the method described in [0117] and [0118] of International Publication No. 2016/017801.

(7) Peel strength

The surface of the laminate of each example on the fluororesin layer side was cut at intervals of 10 mm using a cutter knife, a part of the fluororesin layer was peeled off, and then fixed to the chuck of a tensile testing machine, and the tensile rate was 50 mm/min. The peel strength (N/cm) at the time of peeling by 90 degree|times was measured.

(8) Appearance evaluation

The surface of the fluororesin layer side of the laminated body of each case was confirmed visually, and the following evaluation criteria evaluated it.

Evaluation standard

○: Foaming and cracking are not seen in the fluororesin layer.

x: Foaming or cracking is seen in the fluororesin layer.

[Production Example 1]

Using NAH (hymic anhydride, manufactured by Hitachi Chemical Co., Ltd.) as a monomer forming the unit (1) and PPVE (CF ₂ =CFO(CF ₂ ) ₃ F, manufactured by Asahi Glass Company) as a monomer forming the PAVE unit , Polymer A ¹ was prepared in the order described in International Publication No. 2016/017801 [0123].

The copolymer composition of the prepared polymer A ¹ was NAH unit/TFE unit/PPVE unit = 0.1/97.9/2.0 (mol%). The prepared polymer A ¹ had a melting point of 300°C, an MFR of 17.6 g/10 min, and an average particle size of 1554 µm.

Next, using the prepared polymer A1, ^a resin powder (the produced resin powder is hereinafter referred to as "powder a") was obtained in the procedure described in International Publication No. 2016/017801. The average particle diameter of the powder a was 22.08 m, the small packing bulk density was 0.513 g/ml, and the tightly packing bulk density was 0.686 g/ml.

As a resin powder made of a fluorinated copolymer containing no unit (1), a resin powder made of PFA having no functional group (i) (manufactured by DuPont, trade name “MP-102”) was prepared. Hereinafter, this resin powder is called "powder b". The average particle diameter of the powder b was 14.03 m, the small packed bulk density was 0.8109 g/ml, and the tightly packed bulk density was 1.1351 g/ml.

[Example 1]

The surface of a SUS304 stainless steel sheet having a length of 40 mm, a width of 150 mm, and a thickness of 1.2 mm is sandblasted using 60 mesh alumina particles so that the surface roughness Ra is 5 to 10 µm, and then the surface is cleaned with ethanol , the substrate was prepared.

The operation of electrostatically coating the powder coating material composed of the powder a obtained in Production Example 1 on the surface of the substrate and firing at a firing temperature of 350° C. and a firing time of 4 minutes is repeated 5 times, and further electrostatically coating the powder coating material to a firing temperature The operation of baking at 350 degreeC and 6 minutes of baking time was performed once, and the laminated body in which the 314-micrometer-thick fluororesin layer was formed on the base material was obtained.

[Example 2]

In the same manner as in Example 1, except that the repeated operation of electrostatic coating and firing was changed to an operation of repeating the operation of electrostatically coating the powder coating material and firing at a firing temperature of 370° C. and a firing time of 3 minutes 6 times, A laminate with a fluororesin layer having a thickness of 282 µm was obtained.

[Example 3]

In the same manner as in Example 1, except that the repeated operation of electrostatic coating and firing was changed to an operation of repeating the operation of electrostatically coating the powder coating material and firing the powder coating material at a firing temperature of 330 ° C. and a firing time of 10 minutes 6 times. A laminate with a 252 µm-thick fluororesin layer was obtained.

[Example 4]

In the same manner as in Example 1, except that the repeated operation of electrostatic coating and firing was changed to an operation of repeating the operation of electrostatically coating the powder coating material and firing the powder coating material at a firing temperature of 340° C. and a firing time of 10 minutes 6 times, and A laminate with a 321 µm-thick fluororesin layer was obtained.

[Example 5]

In the same manner as in Example 1, except that the repeated operation of electrostatic coating and firing was changed to an operation of repeating the operation of electrostatically coating the powder coating material and firing at a firing temperature of 380 ° C. and a firing time of 10 minutes 6 times, A laminate with a fluororesin layer was obtained. Foaming was observed in the fluororesin layer of the obtained laminated body, and the film thickness and peeling strength were impossible to measure.

[Example 6]

Using a powder coating material made of powder b as a powder coating material, repeated operations of electrostatic coating and firing, electrostatic coating of powder coating materials, firing at a firing temperature of 340 ° C. and firing time of 10 minutes was changed to an operation repeated 6 times. Except that, it carried out similarly to Example 1, and obtained the laminated body in which the 177-micrometer-thick fluororesin layer was formed on the base material.

[Example 7]

Using a powder coating material made of powder b as a powder coating material, repeated operations of electrostatic coating and firing, electrostatic coating of powder coating material, firing at a firing temperature of 360 ° C. and firing time of 10 minutes was changed to an operation repeated 6 times. Except that, it carried out similarly to Example 1, and obtained the laminated body in which the 139-micrometer-thick fluororesin layer was formed on the base material.

Table 1 shows the manufacturing conditions and evaluation results of each example.

As shown in Table 1, in the laminates of Examples 1 and 2 produced by the production method of the present invention, deterioration in appearance due to foaming or cracking is suppressed, and peel strength is high, and the adhesion between the fluororesin layer and the substrate is high. This was excellent.

On the other hand, the laminates of Examples 3 and 4 in which the firing temperature was 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 seen in the fluororesin layer, and the appearance was inferior. The laminates of Examples 6 and 7 using the resin powder made of a fluorinated polymer containing no unit (1) had lower peel strength than the laminates of Examples 1 and 2, and the adhesion between the fluororesin layer and the substrate was inferior. .

[Example 8]

A substrate was prepared in the same manner as in Example 1.

The operation of electrostatically coating the powder coating material composed of the powder a obtained in Production Example 1 on the surface of the substrate and firing at a firing temperature of 330° C. and a firing time of 10 minutes was repeated twice. Further, P-62X (PFA having no functional group (i), manufactured by Asahi Glass Co., Ltd., PFA having an average particle size of 233 µm) was electrostatically coated and calcined at a calcination temperature of 330°C and a calcination time of 10 minutes, twice, and fluorine on the substrate A laminate was obtained in which the total thickness of the resin layer and the top coat layer was 232 µm.

The peel strength between the fluororesin layer and the base material of the obtained laminate was 17.1 [N/cm], which was excellent in adhesiveness, and foaming and cracking were not observed in the fluororesin layer and the top coat layer, and thus the appearance was also excellent.

Industrial Applicability

The shape and use of the laminate are not particularly limited. As a shape of a laminated body, a pipe, a tube, a film, a board, a tank, a roll, a vessel, a valve, an elbow, etc. are mentioned.

The use of the laminate includes various containers, pipes, tubes, tanks, piping, joints, rolls, autoclaves, heat exchangers, distillation columns, jigs, valves, stirring blades, tank lorries, pumps, blower casings, centrifugal separators, A cooking appliance etc. are mentioned. Moreover, since the laminated body of this invention has the space-saving and excellent insulation, it can be used suitably for an insulation amplifier, an insulation transformer, an alternator of an automobile, the electric motor of a hybrid vehicle, etc.

In addition, all the content of the specification of JP Patent application 2016-201101 for which it applied on October 12, 2016, a claim, and an abstract is referred here, and it takes in as an indication of the specification of this invention.

Claims (15)

A method for manufacturing a laminate comprising a base material and a fluororesin layer, wherein the operation of electrostatically coating the base material and firing the powder coating material is repeated two or more times to form a fluororesin layer having a thickness of 50 µm or more on the surface of the base material As,
The powder coating material contains a resin powder having an average particle diameter of 10 to 500 µm containing the following polymer A,
The manufacturing method of the said laminated body which sets a calcination temperature to 350 degreeC or more and less than 380 degreeC, and sets the total time to set to the said calcination temperature into 60 minutes or less.
Polymer A: a fluorine-containing group having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group and an isocyanate group, and containing a unit based on tetrafluoroethylene, melting point of 260 to 320°C copolymer. The method of claim 1,
The method for producing a laminate, wherein the polymer A is a fluorinated copolymer containing a unit having the functional group. 3. The method according to claim 1 or 2,
The method for producing a laminate, wherein the polymer A is a tetrafluoroethylene/perfluoro(alkylvinyl ether) copolymer having the functional group or a tetrafluoroethylene/hexafluoropropylene copolymer having the functional group. 3. The method according to claim 1 or 2,
The manufacturing method of the laminated body which makes the thickness of the said fluororesin layer 100 micrometers or more. 3. The method according to claim 1 or 2,
The manufacturing method of the laminated body whose said base material is a stainless steel base material. A laminate is produced by the method of claim 1 or 2, and a top coat layer containing a second fluorinated copolymer different from the polymer A is formed on the surface of the fluororesin layer of the obtained laminate. A method for manufacturing a laminate to 7. The method of claim 6,
A method for producing a laminate, wherein the top coat layer is formed by powder coating using a resin powder containing the second fluorinated copolymer. 7. The method of claim 6,
The laminate, wherein the second fluorinated copolymer is a tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer having no functional group or a tetrafluoroethylene/hexafluoropropylene copolymer having no functional group. manufacturing method. A base material and a fluororesin layer, characterized in that by repeating an operation of electrostatically coating a powder coating material on a base material and firing it twice or more, a fluororesin layer is formed on the surface of the base material, and a top coat layer is formed on the fluororesin layer As a manufacturing method of the laminated body provided with,
The total thickness of the fluororesin layer and the top coat layer is 50 μm or more,
The powder coating material for forming the fluororesin layer contains a resin powder having an average particle diameter of 10 to 500 µm containing the following polymer A,
The powder coating material for forming the top coat layer contains a resin powder having an average particle diameter of 10 to 500 µm and containing a second fluorinated copolymer different from the following polymer A;
A method for producing the laminate, wherein the firing temperatures for forming the fluororesin layer and the top coat layer are respectively 330°C or higher and less than 380°C, and the total time at the firing temperature is 60 minutes or less, respectively.
Polymer A: a fluorine-containing group having at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxyl group, an epoxy group and an isocyanate group, and containing a unit based on tetrafluoroethylene, melting point of 260 to 320°C copolymer. 10. The method of claim 9,
The method for producing a laminate, wherein the polymer A is a fluorinated copolymer containing a unit having the functional group. 11. The method according to claim 9 or 10,
The method for producing a laminate, wherein the polymer A is a tetrafluoroethylene/perfluoro(alkylvinyl ether) copolymer having the functional group or a tetrafluoroethylene/hexafluoropropylene copolymer having the functional group. 11. The method according to claim 9 or 10,
The laminate, wherein the second fluorinated copolymer is a tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer having no functional group or a tetrafluoroethylene/hexafluoropropylene copolymer having no functional group. manufacturing method. delete delete delete