JP2005335186A - Laminate containing fluororesin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate containing a fluororesin which has a thin fluororesin layer and heat-resistant adhesive properties equal to a chromium phosphate primer, even when the laminate is calcined at a high temperature for a long time, despite its including a primer layer containing no hexavalent chromium and also has excellent surface smoothness. <P>SOLUTION: This laminate has a coating film (2) of a coating material composition and a fluororesin layer (3) laid in that order on a material to be coated (1), and the coating film (2) is formed of a coating material composition composed of an amide group-containable polymer compound (B) which has an amide group or can have an amide group and an oxidation-resistant substance (C) which can inhibit the oxidation of the amide group. The amide group-containable polymer compound (B) is an amide group-containing polymer (b1) having the amide group and an aromatic ring and/or an amide group-containing polymer precursor (b2) which changes to the amide group-containing polymer (b1). The oxidation-resistant substance (C) accounts for 0.1 to 20 mass% of the sum of the amide group-containable polymer compound (B) and the oxidation-resistant substance (C). Further, the fluororesin layer (3) is less than 200 μm thick. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a fluororesin-containing laminate.

Since the fluororesin is excellent in wear resistance, heat resistance, corrosion resistance, etc., it can be used for coating various objects to be coated. However, since fluororesin has poor adhesiveness due to its non-tackiness, it has poor adhesion to objects to be coated made of metal, ceramic, etc. It is used as a laminate comprising an object to be coated, a primer layer and a fluororesin layer.

A laminate made of a fluororesin can be used as a heating member or the like in a copying apparatus by making use of characteristics excellent in wear resistance and heat resistance.
As a heating member in a copying apparatus, for example, a polymer coating roll having a layer made of tetrafluoroethylene [TFE] primer and a layer made of TFE resin, a layer made of Teflon (registered trademark), and Teflon (registered trademark) Heating members used in toner image fixing devices having a resin layer are known (see, for example, Patent Document 1 and Patent Document 2).

When a laminate made of a fluororesin is usually produced, it is necessary to apply a composition made of the fluororesin on the primer layer and to fire at a temperature equal to or higher than the melting point of the fluororesin. Further, if the object to be coated is large or thick and requires a preheating time, a heat history of a high temperature and a long time is applied during baking during coating. Further, when a laminate made of a fluororesin is used as a heating member or the like in a copying apparatus, it is exposed to a high temperature for a long time during use. Therefore, the primer used for this laminate is required to have heat-resistant adhesion that can maintain adhesion to the object to be coated even after firing at this high temperature.

To date, chromium phosphate primers that have excellent resistance to long-term high-temperature firing have been widely used as primers with excellent heat-resistant adhesion. However, there has been a strong demand for many years to develop a chromium-free primer that does not contain hexavalent chromium and plays a role as a binder component and has strong heat-resistant adhesion comparable to a chromium phosphate primer.

Conventionally, combinations of fluororesin and various binder resins have been studied as chromium-free primers. As the binder resin, use of polyphenylene sulfide [PPS] or polyamideimide [PAI] has been proposed from the viewpoint of heat resistance. However, PPS has a problem in that it has poor compatibility with the fluororesin and has insufficient adhesion to the fluororesin layer. On the other hand, as a laminate using PAI as a primer, a PAI-containing primer is laminated with a first layer, a second layer containing a release resin and a filler, and a third layer made of a release resin alone. A fixing roller has been proposed (see, for example, Patent Document 3).

In order to improve the adhesion with the fluororesin layer, a binder resin in a chromium-free primer has been proposed that contains PPS and PAI and / or polyimide [PI] in a specific ratio (for example, patents). (Ref. Literature 4, Patent Literature 5, and Patent Literature 6). However, chromium-free primers having these binder resins have problems such as poor heat-resistant adhesion and low durability against hot water when fired for a long time.

Furthermore, when a laminate made of a fluororesin is used as a release material, the laminate made of a fluororesin is preferably a thin film. However, in general, a laminate made of a chromium-free primer and a fluororesin generally has a fluororesin layer. If the thickness is not increased, the surface roughness of the primer layer has an effect, and it has been said that the surface smoothness cannot be obtained and the heat-resistant adhesion cannot be achieved.

JP 50-150439 A JP-A-52-107845 JP-A-6-348165 JP-A-53-74532 US Pat. No. 5,789,083 Japanese Patent Laid-Open No. 8-322732

In view of the above-mentioned present situation, the present invention provides a phosphorous resin layer that is thin and baked for a long time at a high temperature even though hexavalent chromium serving as a binder component is not included in the primer layer. An object of the present invention is to provide a fluororesin-containing laminate having a heat-resistant adhesion comparable to that of an acid chromium primer and capable of making the fluororesin layer thin.

The present invention includes an object to be coated (1), a coating film (2) obtained by coating a coating composition on the object to be coated, and a fluororesin layer (3) comprising a fluororesin (A). A fluororesin-containing laminate, in which the article to be coated (1), the coating film (2) and the fluororesin layer (3) are laminated in this order, and the coating composition has an amide group. Or a coating composition comprising an amide group-containing polymer compound (B) that has an amide group and an antioxidant substance (C) that can suppress oxidation of the amide group, The amide group-containing polymer compound (B) is obtained by baking the amide group-containing polymer (b1) having an amide group and an aromatic ring and / or coating the coating composition. Amide group-containing polymer that changes to polymer-containing polymer (b1) It is a precursor (b2), and the antioxidant substance (C) is 0.1 to 20% by mass of the total of the amide group-containing polymer compound (B) and the antioxidant substance (C). The fluororesin layer (3) is a fluororesin-containing laminate characterized by having a thickness of less than 200 μm.
The present invention is described in detail below.

The fluororesin-containing laminate of the present invention includes an object to be coated (1), a coating film (2), and a fluororesin layer (3).
In the fluororesin-containing laminate of the present invention, the article to be coated (1), the coating film (2), and the fluororesin layer (3) are laminated in this order.

The object to be coated (1) is an object to be coated with a coating composition to be described later.
The material to be coated (1) is not particularly limited, and examples thereof include metals such as aluminum, stainless steel [SUS], and iron; heat-resistant resins; ceramics, and the like.

The metal may be a single metal or an alloy, and may be an oxide film rapid forming metal such as stainless steel, copper, or copper alloy in terms of good adhesion to the coating film (2). Alternatively, an oxide film slow-forming metal such as aluminum or iron may be used.
In the present specification, the oxide film rapid-forming metal is a metal that forms an oxide film at least as fast as stainless steel or faster than stainless steel by firing at least in the coating of the coating composition. The oxide film rapid forming metal may be one in which an oxide film has already been formed when the coating composition is applied as an object to be coated. Examples of the oxide film rapid forming metal include stainless steel.
The oxide film rapid forming metal easily forms an oxide film on the surface, and this oxide film is a cause of lowering adhesion with a coating film obtained by applying a conventional coating composition. Conceivable.
In the present specification, the oxide film slow-forming metal is a metal that forms an oxide film slower than stainless steel. Examples of the oxide film slow-forming metal include aluminum and iron.

The coating film (2) is obtained by applying a coating composition.
The said coating film (2) is normally formed on the said to-be-coated article (1).
In the present specification, “coating” means a series of steps comprising applying to an object to be coated such as the object to be coated (1), drying as necessary, and then firing.
The firing is usually carried out by heating on the article to be coated (1) at a temperature equal to or higher than the melting point of the main polymer component constituting the fluororesin-containing laminate of the present invention.
The heating temperature is determined based on whether or not the coating composition contains a fluororesin (D) described later, and the fluororesin (A), the amide group-containing polymer compound (B), the antioxidant substance ( C) and the melting point of the fluororesin (D) described later.

The coating composition includes an amide group-containing polymer compound (B) having an amide group or an amide group, and an antioxidant substance (C) capable of suppressing oxidation of the amide group. ).

The amide group-containing polymer compound (B) is obtained by baking the amide group-containing polymer (b1) having an amide group and an aromatic ring and / or the coating composition. It is an amide group containing polymer precursor (b2) which changes to a containing polymer (b1).
The amide group-containing polymer (b1) is usually a polymer having an amide group (—NH—C (═O) —) in the main chain or side chain and an aromatic ring in the main chain.
The amide group-containing polymer (b1) is preferably polyamideimide [PAI], polyamide, and / or polyamic acid (polyamic acid).
The PAI is a polycondensate having an amide group, an aromatic ring, and an imide group. The PAI is not particularly limited, and for example, in addition to the conventionally known PAI, those in which an amide group is introduced by oxidizing polyimide [PI] can be used.

The polyamide is a polycondensate having an amide bond (—NH—C (═O) —) in the main chain. The polyamide is not particularly limited, and examples thereof include aliphatic polyamides such as nylon 6, nylon 66, nylon 11, and nylon 12; aromatic polyamides such as polyparaphenylene terephthalamide and polymetaphenylene isophthalamide. .
The polyamic acid is a polycondensate having an amide group and a carboxyl group or a carboxyl group derivative. The polyamic acid is not particularly limited, and examples thereof include a polyamic acid having a molecular weight of thousands to tens of thousands.

The amide group-containing polymer precursor (b2) is changed to the amide group-containing polymer (b1) by firing when the coating composition is applied.
The above-mentioned “firing when applying the coating composition” includes (i) “firing” usually performed after applying the coating composition and before laminating the fluororesin layer (3), (ii) above (i) After calcination, “firing” when coating the fluororesin composition described later, or (iii) “firing” when coating the fluororesin composition described later without performing the firing of (i) above. It is a concept that can include any of the firings of (i) to (iii).

As described above, the amide group-containing polymer precursor (b2) is changed to the amide group-containing polymer (b1) by firing when the coating composition is applied. In this firing, the amide group-containing polymer precursor (b2) Since the aromatic ring of the polymer (b1) does not usually change, it has an aromatic ring. However, before applying the coating composition and starting baking, it does not have an amide group. is there.

In the present specification, the polymer compound having an amide group and further having an aromatic ring before applying the coating composition and starting baking is the amide group-containing polymer (b1). It corresponds to.
The amide group-containing polymer precursor (b2) is not particularly limited as long as it changes to the amide group-containing polymer (b1) by applying and baking the coating composition, and examples thereof include PI. May be.

The PI can be oxidized when the coating composition is applied and baked at a high temperature for a long time to introduce an amide group into the main chain. The amide group-containing polymer (b1) obtained by introducing an amide group into the PI is PAI or polyamic acid, and in order to be PAI, all imide groups in the main chain of PI were converted to amide groups. The polyamic acid may be a polyamic acid obtained by converting all of the imide groups in the main chain of PI into amide groups and carboxyl groups.

The method for introducing an amide group into the PI is not particularly limited. For example, a method of opening the imide group (imide ring) of PI by oxidation, or hydrolysis by causing an alkali to act on the imide group (imide ring) of PI. Methods and the like. In the present specification, a site on a molecular structure into which an amide group is to be introduced, for example, an imide group that is changed to an amide group by the above-described oxidation may be referred to as an amide group introduction site.

The amide group-containing polymer compound (B) has an amide group or has an amide group.
The above-mentioned “being having an amide group” means that the amide group-containing polymer compound (B) is not necessarily present at the time when the amide group-containing polymer compound (B) is blended in order to prepare the coating composition. Although it does not need to have an amide group, it means that a chemical change is caused by baking at the time of applying the coating composition described above, and the amide group is introduced before the baking is completed.
In the present specification, the above-mentioned “has an amide group or will have an amide group” means that at the time of blending the amide group-containing polymer compound (B) in order to prepare the coating composition, It is a concept that can include any of those having an amide group and no amide group introduction site, those having no amide group and having an amide group introduction site, those having an amide group and having an amide group introduction site. is there. That is, the coating composition may contain both the amide group-containing polymer (b1) and the amide group-containing polymer precursor (b2), or only one of them. Also good.

The said antioxidant substance (C) can suppress the oxidation of the said amide group. The antioxidant substance (C) has a redox potential lower than the redox potential of the amide group and is comparable to the redox potential of the imide group or compared to the redox potential of the imide group. A higher one is preferable, and a higher one is more preferable than the redox potential of the imide group.

It is considered that the antioxidant substance (C) can delay the oxidation of the amide group by being auto-oxidized in preference to the oxidation of the amide group. As said antioxidant substance (C), the substance with a low oxidation state is considered preferable from the point which can fully suppress the oxidation of the said amide group. As said antioxidant substance (C), while being able to suppress the oxidation of the said amide group, it is more preferable that it is a heat resistant substance. If the antioxidant substance (C) is a heat-resistant substance, the antioxidant substance (C) is less likely to be decomposed or deteriorated even if firing is performed for a long time when the coating composition is applied. Oxidation of the amide group can be continuously suppressed, and adhesion between the coating film (2) and the object to be coated (1) by the amide group-containing polymer compound (B) can be maintained.

The antioxidant substance (C) may have a reducing ability to reduce the oxidized amide group in addition to the self-oxidizing ability to self-oxidize in preference to the oxidation of the amide group.
The antioxidant substance (C) may have a property of suppressing oxidation of an object to be coated in addition to the property of suppressing oxidation of the amide group described above.

Examples of the antioxidant substance (C) include polyarylene sulfide [PAS]; nitrogen-containing compounds; metals such as tin, zinc and phosphorus; sulfur and the like.
The PAS is not particularly limited, and examples thereof include polyphenylene sulfide ketone, polyphenylene sulfide sulfone, polybiphenylene sulfide, and polyphenylene sulfide [PPS]. Among these, PPS is preferably used. PAS is preferably used when the use of amines or elution of metal ions is disliked in semiconductor manufacturing processes.

The “nitrogen-containing compound” is a compound having a nitrogen atom in the molecule, and can suppress both oxidation of the amide group and oxidation of the object to be coated.
Examples of the nitrogen-containing compound include amine compounds, benzotriazole compounds, nitrogen sulfur-containing compounds, and the like.

The amine compound is a compound having an amino group, and the amino group may form a salt such as a metal salt. Although it does not specifically limit as said amine compound, Aromatic amines are preferable at the point from which the high temperature stability in 250 degreeC or more is desired. As the aromatic amines, those having a phenyl group and / or naphthyl group are preferable, and the aromatic amines having a phenyl group and / or naphthyl group are not particularly limited, and examples thereof include dinaphthylamine and phenyl-α-naphthylamine. , Phenyl-β-naphthylamine, diphenyl-p-phenylenediamine, phenylcyclohexyl-p-phenylenediamine, and the like.

The benzotriazole-based compound is a compound having a chemical structure having benzotriazole as a basic skeleton, and may form a salt such as a metal salt. The benzotriazole-based compound is not particularly limited, and examples thereof include benzotriazole, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-tetraoctylphenyl) benzotriazole, and the like. It is done.

The nitrogen-sulfur-containing compound is a compound having a nitrogen atom and a sulfur atom, and may form a salt such as a metal salt.
The nitrogen-sulfur-containing compound is not particularly limited, and examples thereof include benzothiazole compounds, sulfenamide compounds, and thioureas. The benzothiazole compound is not particularly limited as long as it is a compound having benzothiazole as a basic skeleton. For example, 2-mercaptobenzothiazole, di-2-benzothiazole disulfide, 2- (N, N′-diethylthiocarbamoyl) Thio) benzothiazole, di-2-benzothiazolyl disulfide and the like.

The sulfenamide-based compound is not particularly limited as long as it is a compound having a sulfenamide group. For example, N, N′-cyclohexyl-benzothiazolylsulfenamide, N-tert-butyl-2-benzothia Zolylsulfenamide, N-oxydiethylene-2-benzothiazolylsulfenamide, N, N'-dicyclohexyl-2-benzothiazolylsulfenamide, N, N'-diisopropylbenzothiazole-2-sulfenamide, etc. Is mentioned.
In the present specification, the sulfenamide-based compound is a concept including a compound having a sulfenamide group and a structural portion having benzothiazole as a basic skeleton.

The thioureas are preferably thioureas in which at least one hydrogen atom bonded to the nitrogen atom may be substituted with a saturated or unsaturated hydrocarbon group having 1 to 6 carbon atoms. Such thioureas Is not particularly limited, and examples thereof include N, N′-diethylthiourea, N, N′-dibutylthiourea, thiourea, and N, N′-diphenylthiourea.

As the nitrogen-containing compound, a benzothiazole-based compound is preferably used, and among the benzothiazole-based compounds, a zinc-based antioxidant that is a salt with zinc is particularly preferably used.

As said antioxidant substance (C), 1 type (s) or 2 or more types can be used in combination.
When PAS and another antioxidant substance are used in combination as the antioxidant substance (C), the PAS and the other antioxidant substance are in a mass ratio of PAS: other antioxidant substance = The combination is preferably 50:50 to 99: 1, and the combination is more preferably PAS: other antioxidant substance = 70: 30 to 90:10.
As said other antioxidant substance, things other than PAS are mentioned among the above-mentioned antioxidant substances (C), Especially, a nitrogen-containing compound is used preferably. Examples of the other antioxidant substances include nitrogen-containing compounds; metals such as tin, zinc and phosphorus; sulfur and the like.

As the antioxidant substance (C), PAS and / or nitrogen-containing compounds are preferably used.
As the antioxidant substance (C), when the article to be coated (1) is made of an oxide film rapid-forming metal that easily forms an oxide film, the nitrogen-containing compound is preferably used. The nitrogen-containing compound is preferably used in combination with PAS in terms of improving adhesion with (1).
As the antioxidant substance (C), when the article to be coated (1) is made of a metal that slowly forms an oxide film, the nitrogen-containing compound may be used. The nitrogen-containing compound does not have to be used in that the adhesion with the object to be coated (1) is not significantly reduced by baking in the coating, and it does not necessarily have the property of suppressing the oxidation of the object to be coated (1). However, it is sufficient to use those having the property of suppressing the oxidation of the above-mentioned amide group. For example, only PAS may be used.

In the fluororesin-containing laminate of the present invention, the particles made of the antioxidant substance (C) preferably have an average particle size of 20 μm or less.
In the fluororesin-containing laminate of the present invention, the fluororesin layer (3) can be easily thinned by reducing the average particle diameter of the particles comprising the antioxidant substance (C) within the above range. That is, even if the fluororesin layer (3) is a thin film, the surface of the coating film (2) can be smoothed, so that the smoothness of the surface of the fluororesin-containing laminate can be improved, and heat resistant adhesion Will not be damaged.
If the average particle diameter of the particles comprising the antioxidant substance (C) is within the above range, the preferable lower limit can be 0.01 μm, the more preferable lower limit can be 0.1 μm, and the preferable upper limit can be 17 μm.

The said antioxidant substance (C) is 0.1-20 mass% of the sum total of the said amide group containing high molecular compound (B) and the said antioxidant substance (C). If it exceeds 20% by mass, the adhesion after hot water treatment tends to decrease, and if it is less than 0.1% by mass, the adhesion after heat treatment tends to decrease. When used in combination, the mass of the antioxidant substance (C) is the total mass of all the antioxidant substances (C) combined.

When PAS is used alone as the antioxidant substance (C), PAS is preferably 1 to 20% by mass of the total of the amide group-containing polymer compound (B) and PAS. If it is less than 1% by mass, the adhesion after heat treatment tends to be reduced. When it exceeds 20 mass%, the adhesive force after a hot-water process will fall easily. A preferable lower limit is 3% by mass, a preferable upper limit is 18% by mass, a more preferable lower limit is 5% by mass, and a more preferable upper limit is 15% by mass.

When a nitrogen-containing compound is used alone as the antioxidant substance (C), the nitrogen-containing compound is 0.1 to 5 mass in total of the amide group-containing polymer compound (B) and the nitrogen-containing compound. % Is preferred. If it is less than 0.1% by mass, the adhesion after heat treatment tends to be reduced. When it exceeds 5 mass%, the initial adhesion strength and the adhesion strength after the hot water treatment tend to be reduced. A more preferred upper limit is 3% by mass, and a still more preferred upper limit is 1% by mass.

The coating composition is preferably composed of the amide group-containing polymer compound (B), the antioxidant substance (C), and further a fluororesin (D).
When the coating composition is the one to which the fluororesin (D) is added, the fluororesin (D) layer containing the fluororesin (D) as a main component and the amide group-containing polymer are coated by coating. The coating film (2a) divided into the two-layer structure of the second layer mainly composed of the compound (B) and the antioxidant substance (C) can be formed.

In the present specification, the coating film (2a) divided into the two-layer structure is said to be “divided into two-layer structure” in the present specification, but in reality, the amide group-containing polymer compound is closer to the object to be coated (1). The concentration of (B) and the antioxidant substance (C) is high, and the concentration of the fluororesin (D) instead of the antioxidant substance (C) increases as the distance from the object to be coated (1) increases. It is considered that the fluororesin (D) is present at a high concentration on the outermost surface. Therefore, the coating film (2) includes a layer made of a fluororesin (D) and a layer made of an amide group-containing polymer compound (B) and an antioxidant substance (C) depending on the blending amount of each component. In some cases, there may be a so-called intermediate layer composed of the amide group-containing polymer compound (B) and the fluororesin (D).
When the coating composition contains the fluororesin (D), the resulting fluororesin-containing laminate is compatible with the fluororesin (A) in the fluororesin layer (3) and the fluororesin (D). By this, it becomes what was excellent in the adhesiveness of a coating film (2) and a fluororesin layer (3).

In the coating composition, the fluororesin (D) preferably has a baking temperature of 300 ° C. or higher during coating.
The firing temperature during the coating is generally higher than the higher of the melting point of the fluororesin (A) or the melting point of the fluororesin (D). The firing at the time of coating may be the same as the “baking at the time of coating the coating composition” described above for the amide group-containing polymer precursor (b2).
The coating composition is less susceptible to a decrease in adhesion with the object to be coated (1) even after firing for a long time of several tens of hours at a temperature of 300 ° C. or higher. Such excellent heat-resistant adhesion can be achieved conventionally only by using a chromium-based primer. However, the coating composition described above is hexavalent chromium or hexavalent chromium which plays a role of a binder component. Excellent heat-resistant adhesion can be achieved without using a compound.

The fluororesin (D) is made of a polymer obtained by polymerizing a monomer having fluorine.
In the said fluororesin (D), the said polymer may exist 1 type (s) or 2 or more types.

Examples of the fluororesin (D) include chlorotrifluoroethylene [CTFE], trifluoroethylene, tetrafluoroethylene [TFE], hexafluoropropylene [HFP], vinylidene fluoride [VdF], and perfluoro (alkyl vinyl). It is preferably a fluorine-containing polymer obtained by polymerizing one or more fluorine-containing monomers selected from the group of fluorine-containing monomers consisting of ether [PAVE], This fluorine-containing polymer is one or two or more fluorine-free monomers selected from the above-mentioned one or two or more fluorine-containing monomers and a fluorine-free monomer group such as ethylene and propylene. And may be obtained by copolymerization of

The fluororesin (D) is more preferably made of a tetrafluoroethylene copolymer in terms of corrosion resistance.
In the present specification, the “tetrafluoroethylene copolymer” is obtained by polymerizing TFE and fluorine-containing monomers and / or fluorine-free monomers other than TFE in the fluorine-containing monomer group described above. It is the obtained polymer. You may use 1 type (s) or 2 or more types, respectively, as a fluorine-containing monomer other than said TFE, and the said fluorine-free monomer.

As the fluororesin (D), a resin having a melting point lower than the firing temperature at the time of coating and having heat resistance at the firing temperature is more preferable.
As the fluororesin (D), a perfluoro resin is preferably employed because it has both corrosion resistance and heat resistance.

The perfluoro resin is usually a resin that requires a baking temperature of 300 ° C. or higher, and is obtained by polymerizing perfluoroolefin with perfluorovinyl ether and / or a small amount of a comonomer. It consists of coalescence. It does not specifically limit as said perfluoro olefin, For example, TFE, HFP, etc. are mentioned. The perfluorovinyl ether is not particularly limited, and examples thereof include perfluoro (methyl vinyl ether), perfluoro (ethyl vinyl ether), and perfluoro (propyl vinyl ether).

As said trace amount comonomer, the said fluorine-containing monomer which is neither perfluoroolefin nor perfluoro vinyl ether, and / or a fluorine-free monomer can be used 1 type, or 2 or more types. The repeating unit derived from the trace comonomer in the molecular chain of the perfluoro polymer is preferably less than 10 mol% of the total monomer units of the perfluoro polymer.

The fluororesin-containing laminate of the present invention further improves the adhesion between the coating film (2) and the fluororesin layer (3) by using a resin comprising a polymer having a terminal functional group as the fluororesin (D). It can be improved.

There are no particular restrictions regarding the terminal functional groups, e.g., -COOR ^{1 (R 1} represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms, or represents a perfluoroalkyl group having 1 to 3 carbon atoms.), —COF, —CONH ₂ , —CH ₂ OH, —COOM ¹ , —SO ₄ M ² , —SO ₃ M ³ (M ¹ , M ² and M ³ may be the same or different and may be a group I atom or a monovalent cation. Represents an atomic group capable of becoming an ion.), —SO ₄ M ⁴ _1/2 , —SO ₃ M ⁵ _1/2 (M ⁴ and M ⁵ are the same or different and are a transition of a group II atom, iron, etc. Represents an atomic group that can be a metal or a divalent cation.). Examples of the group I atom include a hydrogen atom, a sodium atom, and a potassium atom, and examples of the atomic group that can be a monovalent cation include an ammonium group. Examples of the group II atom include calcium and magnesium. As a transition metal, iron etc. are mentioned, for example.
The amount of the terminal functional group is preferably in the range of 50 to 100,000 per million carbon atoms in the polymer molecular chain of the fluororesin (D). When the number is less than 50, the adhesive force tends to be reduced, and when it exceeds 100000, foaming during firing becomes violent and a coating film defect is likely to occur. The amount of the terminal functional group is more preferably 100 per million carbon atoms in the polymer molecular chain of the fluororesin (D), and a further preferred lower limit is 200, and a more preferred upper limit is 50,000. Furthermore, a more preferable upper limit is 10,000 pieces.
The amount of the terminal functional group is a value that can be measured using an infrared spectrophotometer.

The amount of the terminal functional group in the polymer having the terminal functional group can be usually adjusted by polymerizing by selecting an appropriate catalyst, a chain transfer agent and polymerization conditions.
The amount of the functional group in the polymer having the terminal functional group can be increased by polymerizing the monomer having the functional group.
By reacting the polymer of the fluororesin (D) obtained by polymerizing the monomer having the functional group as a monomer with a reaction reagent such as an acid or an alkali and treating with heat, the above (terminal) functional group is obtained. The group is partially altered in chemical structure by the action of reaction reagents and heat.

As the fluororesin (D), a dispersion or powder obtained by emulsion polymerization or suspension polymerization can be used, and furthermore, fine powder obtained by pulverization and pulverization can be used.

When the fluororesin (D) is used as a powder, the average particle size is preferably 0.1 to 50 μm. When the thickness is less than 0.1 μm, the interlayer adhesion between the coating film (2) and the fluororesin layer (3) is lowered, and when it exceeds 50 μm, the surface smoothness of the coating film (2) may be deteriorated. In terms of facilitating the thinning of the fluororesin layer (3), the more preferable lower limit of the average particle diameter of the fluororesin (D) is 0.5 μm, the more preferable upper limit is 30 μm, and the further preferable upper limit is 10 μm.
In the present specification, the average particle diameter is a value that can be measured by a laser measurement method.

When the amide group-containing polymer compound (B) is used as a particle state in the coating composition, the average particle size of the particles made of the fluororesin (D) is the amide group-containing polymer compound (B). It is preferable that the average particle diameter of the particles made of and the particles made of the antioxidant substance (C) is relatively large.
In this case, the average particle diameter of the particles composed of the amide group-containing polymer compound (B) is preferably 20 μm or less, as in the case of the particles composed of the antioxidant substance (C). If it is in the said range, a preferable minimum can be 0.01 micrometer and a more preferable minimum can be 0.1 micrometer.

It is preferable that the said fluororesin (D) is 50-90 mass% of the sum total of the said amide group containing high molecular compound (B), the said antioxidant substance (C), and the said fluororesin (D). When it is less than 50% by mass, the adhesion between the coating film (2) and the fluororesin layer (3) tends to be poor, and when it exceeds 90% by mass, the coating film (2) and the article to be coated (1). Adhesion with is easy to deteriorate. A more preferable lower limit is 60% by mass, and a more preferable upper limit is 85% by mass.
The said numerical range is a value about solid content mass of a fluororesin (D). When preparing the coating composition, the solid content mass of the fluororesin (D) may be blended with the fluororesin (D) as a liquid as described above. It is a value corresponding to the dry mass of the powder obtained by taking out the particles comprising the fluororesin (D) in the liquid.

In order to improve the film forming property, corrosion resistance, and the like of the resulting coating film (2), the coating composition is prepared by using the amide group-containing polymer compound (B) or the antioxidant substance (C) as necessary. Or other resin which is not any of the fluororesin (D) and has heat resistance of 200 ° C. or more may be blended.

It does not specifically limit as said other resin, For example, polyether sulfone resin, polyether ether ketone resin, polyether ketone resin etc. are mentioned, These can use 1 type (s) or 2 or more types.

The coating composition may contain additives in order to improve the coating workability and the properties of the coating film (2) as necessary.
The additives are not particularly limited, and for example, leveling agents, solid lubricants, pigments, glittering materials, fillers, pigment dispersants, anti-settling agents, moisture absorbers, surface conditioners, thixotropic agents, viscosity Conditioner, Anti-gelling agent, UV absorber, Light stabilizer, Plasticizer, Anti-color separation agent, Anti-skinning agent, Anti-scratch agent, Antifungal agent, Antibacterial agent, Anticorrosive agent, Antistatic agent, Silane A coupling agent etc. are mentioned.
In this specification, the said anti-corrosive agent means what has a property which does not suppress the oxidation of an amide group, but suppresses the oxidation of a to-be-coated object (1).
The fluororesin-containing laminate of the present invention is suitable for applications where hardness is required, such as kitchen applications, when the coating (2) is obtained from a coating composition to which mica is added as the additive. is there.

The coating composition can be produced by either a powder coating type or a liquid coating type. In the coating composition, the amide group-containing polymer compound (B) and the antioxidant substance (C) may be dissolved in an appropriate solvent and used as a solution.
The coating composition is preferably a liquid coating type in that the coating composition can be uniformly applied to the object to be coated (1).
As the liquid paint type, an amide group-containing polymer compound (B) and an antioxidant substance (C) are dissolved or dispersed in a dispersion in which particles made of a fluororesin (D) are dispersed in a dispersion medium. It is preferable that

When the coating composition is a liquid coating type in which the above-mentioned other resin is blended, it usually depends on the type of the dispersion medium and the solubility of the other resin, but usually contains particles made of the other resin. It may be dispersed in the dispersion medium.

As the dispersion medium, water, an organic medium, or a mixed solvent of water and the organic medium can be used.
When water is used as the dispersion medium, a cationic surfactant, an anionic surfactant, or a nonionic surfactant can be dispersed as a dispersant, but it is difficult to remain in the coating film (2). Nonionic surfactants are preferably used. When water is used as the dispersion medium, a fluorine-based surfactant may be used in combination.

The organic medium is not particularly limited. For example, lower alcohols such as 1-butanol and diacetone alcohol; ketones such as methyl isobutyl ketone and methyl ethyl ketone; esters such as butyl acetate; N-methyl-2-pyrrolidone; Amides such as N, N-dimethylacetamide, N, N-dimethylformamide; aromatic hydrocarbons such as toluene, xylene, trimethylbenzene, methylethylbenzene, propylbenzene, butylbenzene, etc. The above can be used.

When the coating composition does not contain a fluororesin (D), the above-mentioned amide group-containing polymer compound (B) and antioxidant substance (C) and the above-mentioned other resins used as desired are used. It can be obtained as a binder resin liquid material dissolved or dispersed in an organic medium and / or water.

When the coating composition contains a fluororesin (D), it can be prepared by a method of stirring and mixing the fluororesin (D) dispersion and the binder resin liquid.
The fluororesin (D) dispersion is obtained by wetting the particles made of the fluororesin (D) with the above-mentioned dispersion medium and then dispersing with a dispersant such as a nonionic surfactant or an anionic surfactant. The dispersion medium can be obtained by a method in which the surface tension of the dispersion medium is lowered with a fluorine-based surfactant or the like to disperse the particles made of the fluororesin (D).

The stirring and mixing is preferably performed using a pulverizing and dispersing machine such as a basket mill, a dynamo mill, or a ball mill.
After the stirring and mixing, the coating composition may be diluted with a poor solvent as necessary to adjust the viscosity.

In the fluororesin-containing laminate of the present invention, the coating film (2) preferably has a thickness of 1 to 20 μm. If the thickness of the coating film (2) is less than 1 μm, the heat-resistant adhesion tends to be inferior, and if it exceeds 20 μm, the surface smoothness of the coating film (2) may be impaired. The thickness of the coating film (2) can be easily reduced, for example, by reducing the average particle diameter of the particles made of the antioxidant substance (C) within the above range.

The said fluororesin layer (3) consists of a fluororesin (A).
The fluororesin layer (3) is usually formed on the coating film (2).
When the coating composition contains the fluororesin (D), the surface of the coating film (2) contains a large amount of the fluororesin (D), so the fluororesin layer (3) In the case where it is formed in contact with (2), the fluororesin (A) has the same or similar composition as the fluororesin (D) in the sense of enhancing compatibility and adhesion with the surface of the coating film (2). It is preferable to use a fluororesin having
As said fluororesin (A), even if the said coating composition does not contain a fluororesin (D), you may use the same thing as the fluororesin (D) mentioned above.

When the fluororesin layer (3) is formed in contact with the coating film (2), if the coating composition contains the fluororesin (D) described above, the fluororesin layer (3) is in close contact with the coating film (2). It may contain a fluororesin (D) together with the fluororesin (A) in terms of enhancing the properties.

The said fluororesin layer (3) can be obtained by normally coating the fluororesin composition which consists of a fluororesin (A) on the said coating film (2).
In the fluororesin composition, a powder paint type and a liquid paint type are selectively used depending on a desired film thickness, similarly to the paint composition. The surface smoothing and thinning of the fluororesin layer (3) can be easily achieved with a liquid paint, but even with a powder paint, the average of the antioxidant substance (C) and fluororesin (D) described above This can be achieved by adjusting the particle diameter, the film thickness of the coating film (2), and the like.
The fluororesin composition may contain the same dispersion medium, dispersant, additive, other resin, and the like as the coating composition.
The fluororesin layer (3) has a thickness of less than 200 μm.
If the said thickness is in the said range, 10 micrometers or more may be sufficient, Preferably it may be 20 micrometers or more. A preferable upper limit of the thickness is 100 μm, and a more preferable upper limit is 80 μm.

The fluororesin-containing laminate of the present invention may further include other layers as long as it includes the article to be coated (1), the coating film (2), and the fluororesin layer (3). .
The fluororesin-containing laminate of the present invention is preferably composed only of an object to be coated (1), a coating film (2) and a fluororesin layer (3).
Hereinafter, the method for producing a fluororesin-containing laminate of the present invention will be described by taking as an example a construction composed only of an article to be coated (1), a coating film (2) and a fluororesin layer (3).

In the fluororesin-containing laminate of the present invention, preferably, the coating composition (1) is applied to the coating composition (1), and the coating film (2) is applied to the fluororesin composition. It can be produced by laminating the fluororesin layer (3).
In the preparation, the object to be coated (1) is subjected to the removal of the resin component and the surface roughening treatment from the point that the adhesion with the coating film (2) can be improved prior to the coating of the coating composition. Preferably it is done.
Examples of the method for removing the resin component include a method using an organic solvent, an alkali and the like; a method of decomposing the resin component at a temperature of 300 ° C. or higher.

The coating film (2) is coated with the coating composition, optionally dried at 80 to 150 ° C. for 10 to 60 minutes, and then fired under known conditions to form the article to be coated (1). Can be formed on top.
Firing to form the coating film (2) may be performed before the above-described fluororesin composition is applied, or not performed before the fluororesin composition is applied, and simultaneously with the firing of the fluororesin composition. You may do it.
The fluororesin layer (3) is usually coated on the obtained coating film (2) so that the thickness after drying of the fluororesin composition is less than 200 μm. Baking is performed for 30 to 120 minutes at a temperature equal to or higher than the melting point or higher than the melting point of the fluororesin (D). When the melting point of the fluororesin (A) and the melting point of the fluororesin (D) are different, the firing temperature is set to a higher temperature than the higher one.

The use of the fluororesin-containing laminate of the present invention is not particularly limited, but the thickness of the fluororesin layer (3) is as thin as the above range, and is suitable for uses exposed to high temperatures during firing and use during coating. It is.
Examples of applications that are exposed to high temperatures during baking during coating include those that require preheating time because the object to be coated is large or thick. Among these, the fluororesin-containing laminate of the present invention can be suitably used as a laminate comprising a large and / or thick article to be coated and a thin fluororesin layer. For example, the fluororesin layer (3) For example, a papermaking roll.
Examples of uses exposed to high temperatures in use include uses where the fluororesin layer (3) is used as a release material, for example, heat fixing rolls or heat fixing belts used in office automation [OA] equipment.

Conventionally, the fluororesin-containing laminate of the present invention has a surface smoothness that has been considered to be achieved without increasing the thickness of the fluororesin layer despite having a chromium-free primer layer containing a binder resin such as PPS. The heat-resistant adhesion can be achieved despite the fact that the thickness of the fluororesin layer (3) is within the above range.

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples.

Example 1
Polyamideimide resin [PAI] (manufactured by Hitachi Chemical Co., Ltd., 30% N-methyl-2-pyrrolidone solution) 10.00 g, tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer [PFA] (melting point: 310 ° C.) , Average particle size: 20 μm) 6.66 g, polyphenylene sulfide resin [PPS] (manufactured by Kureha Chemical Co., Ltd., average particle size: 15 μm) 0.33 g, N-methyl-2-pyrrolidone 13.80 g, methyl isobutyl ketone 9.20 g In addition to the above mixed solvent, a dispersion composition (trade name: Three-One Motor, manufactured by Shinto Kagaku Co., Ltd.) was used for dissolution and dispersion to obtain a coating composition.

Iron plate (SS400; length 100 mm × width 50 mm × thickness 1.5 mm; average roughness [Ra] using alumina powder (trade name: Tosa Emery # 40, manufactured by Ujiden Chemical Co., Ltd.) with a spraying pressure of 1.0 MPa ] = 2 to 3 μm, measured using a surface roughness profile measuring machine Surfcom 470A (manufactured by Tokyo Seimitsu Co., Ltd.) according to JIS B0601.) On the coating composition, the dry film thickness is 30 μm. Spray-coated and dried at 120 ° C. for 30 minutes. PFA powder paint (average particle size: 20 μm; melt flow rate: 6 g / 10 min, measured in accordance with ASTM D3307) on the obtained coating film (2), the total film thickness after firing is 180 μm. Was placed and fired at 350 ° C. for 1 hour to obtain a fluororesin-containing laminate A.

A test piece (length 100 mm × width 10 mm) was cut out from the obtained fluororesin-containing laminate A and evaluated as follows.
A test piece having a width of 10 mm in a heat resistance test was placed in an electric furnace at 350 ° C., heated for 20 hours, 30 hours or 50 hours, then returned to room temperature, and JIS K 6854-1 using a Tensilon universal testing machine. (1999), the peel adhesion strength was measured in the 90 ° direction with respect to the test piece at a pulling speed of 50 mm / min. However, when the coating film of the test piece peeled after the heating, the peel adhesion strength was 0 kg / cm. The results are shown in Table 1.

Heat-resistant water treatment test A test piece with a cut width of 10 mm was immersed in hot water at 90 ° C. or higher for 24 hours, 72 hours or 120 hours, then returned to room temperature, and subjected to the test piece in the same manner as the heat resistance test. The peel adhesion strength was measured in the 90 ° direction. The results are shown in Table 2.

Evaluation of peeled state In the above peel adhesion strength test, the peeled state was observed and evaluated as follows.
/ A: Peeling between substrate and coating film (2) [base peeling]
/ B: Peeling between the coating film (2) and the PFA resin layer [interlayer peeling]
/ C: Peeling due to destruction of coating film (2) [cohesive failure]
/ D: peeling due to breakage of fluororesin layer (3)

Example 2
A fluororesin-containing laminate B was produced in the same manner as in Example 1 except that the PAI of Example 1 was 11.00 g and the PPS was 0.03 g, and the same evaluation as in Example 1 was performed.

Example 3
Fluorine as in Example 1 except that 11.00 g of PAI of Example 1 and 0.03 g of a benzothiazole compound [2-mercaptobenzothiazole zinc salt], which is a zinc-based antioxidant, were used as an antioxidant. A resin-containing laminate C was prepared and evaluated in the same manner as in Example 1.

Comparative Example 1
A comparative laminate was obtained and evaluated in the same manner as in Example 1 except that 6.00 g of PFA was used and no PPS was added.

Comparative Example 2
A comparison was made in the same manner as in Example 1 except that a chromium phosphate primer (trade name: 850-314 / VM7799 = 100/35, manufactured by DuPont) was used instead of the coating composition used in Example 1. A laminate was obtained and evaluated.

From Table 1, the peel adhesion strength after a long-term heat resistance test is significantly reduced in Comparative Example 1 in which PPS was not used, but not in Comparative Example 2 in which a chromium phosphate primer was used. 1 to 3, it was found that the peel adhesion strength was maintained to the same extent as in Comparative Example 2.
From Table 2, the peel adhesion strength after the hot water test is remarkably reduced in Comparative Example 2 using the chromium phosphate primer, but is not reduced in Comparative Example 1 using no PPS. Thus, it was found that the peel adhesion strength was maintained to the same extent as in Comparative Example 1.
In Tables 1 and 2, in Examples 1 to 3, since there was no peeling state of A, B, and C, the coating film (2) did not cause cohesive failure, and heat-resistant adhesion with the object to be coated (1) It was found that both the heat resistance and the heat-resistant adhesion to the fluororesin layer (3) are excellent.

Since the fluororesin-containing laminate of the present invention has the above-described configuration, the coating film (2) is obtained from a chromium-free primer, and the thickness of the fluororesin layer (3) is within the above range. Despite being thin, it is excellent in surface smoothness and heat-resistant adhesion, so that it can also be suitably used in applications where it is exposed to high temperatures during firing and use during coating.

Claims (7)

Fluororesin-containing laminate comprising an article to be coated (1), a coating film (2) obtained by painting a coating composition on the article to be coated, and a fluororesin layer (3) comprising the fluororesin (A) Body,
The object to be coated (1), the coating film (2) and the fluororesin layer (3) are laminated in this order,
The coating composition has an amide group-containing polymer compound (B) having an amide group or having an amide group, and an antioxidant substance (C) capable of suppressing oxidation of the amide group. A coating composition comprising:
The amide group-containing polymer compound (B) is prepared by subjecting the amide group-containing polymer (b1) having an amide group and an aromatic ring, and / or baking to coat the coating composition. An amide group-containing polymer precursor (b2) that changes to a containing polymer (b1),
The antioxidant substance (C) is 0.1 to 20% by mass of the total of the amide group-containing polymer compound (B) and the antioxidant substance (C),
The fluororesin layer (3) is a fluororesin-containing laminate having a thickness of less than 200 μm. The fluororesin-containing laminate according to claim 1, wherein the coating composition further comprises a fluororesin (D). The fluororesin-containing laminate according to claim 1 or 2, wherein the coating film (2) has a thickness of 1 to 20 µm. The fluororesin-containing laminate according to claim 1, 2 or 3, wherein the particles comprising the antioxidant substance (C) have an average particle diameter of 20 µm or less. The fluororesin-containing laminate according to claim 1, 2, 3, or 4, wherein the fluororesin layer (3) is a release material. 5. The fluororesin-containing laminate according to claim 1, which is a heat fixing roll or a heat fixing belt. The fluororesin-containing laminate according to claim 1, which is a papermaking roll.